section 3 of Histology of the Blood. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Reading by Bologna Times. Histology of the Blood by Paul Ehrlich and Adolf Lazarus. Translated by M. Myers. Section 3. B. Normal and Pathological Histology of the Blood. Insatisfactorily, prepared dry specimens, the red blood-core puzzles, keep their natural size and shape, and their bicon cavity is plainly seen. They present a distinct round homogeneous form of about 7.5 microns in diameter. They are most intensely colored in a broad peripheral layer, and most faintly in the center, corresponding to their depression. With all stains mentioned above, the stroma is quite uncolored, and the hemoglobin exclusively attracts the stain, so that for a practiced observer the depth of stain gives a certain indication of the hemoglobin equivalent of each cell, and a better one than the natural color of the hemoglobin in the fresh specimen. Corpuscles poor in hemoglobin are easily recognized by their fainter staining, especially by the still greater brightness of the central zone. When somewhat more marked, they present appearances which from the isolated staining of the periphery, Lytton has happily named pessary forms. The faint staining of a red corpuscle cannot be explained, as Igrovitz assumes by a diminished affinity of the hemoglobin for the dye. Qualitative changes of this kind of the hemoglobin expressing themselves in an altered relationship towards dyes do not occur, even in anemic blood. If in the latter the blood discs stain less intensely, this is due exclusively to the smaller amount of hemoglobin. A diminution in the hemoglobin content can in this way be shown in all anemic conditions, especially in post hemorrhagic, secondary, and chlorotic cases. On the contrary, as Lach first observed in the pernicious anemias, the hemoglobin equivalent of the individual discs is raised. To appreciate correctly pathological conditions it must always be borne in mind that in normal blood the individual red blood corpuscles are by no means of the same value. Step by step some of the cells are used up and replaced by new. Every drop of blood contains side by side the most various stages of life of fully formed erythrocytes. For this reason influences which affect the blood provided their intensity does not exceed a certain degree cannot equally influence all red corpuscles. The least resistant elements, that is the oldest, will succumb to the effect of influences to which other and more vigorous cells adapt themselves. To influences of this moderate degree belongs without doubt the anemic constitution of the blood as such, the effect of which is in this direction one can best investigate in cases of post hemorrhagic anemia. In all anemic conditions we observe characteristic changes in the blood discs. A. anemic or polychromatophyll degeneration. This change in the red blood corpuscles first described by Erlich to which the second name was given later by Ghebreczewski is only recognizable in stained preparations. The red blood discs which under normal circumstances stain in pure hemoglobin color now take on a mixed color. For instance the red corpuscles are pure red in preparations of normal blood stained with hematoxilin, eosin, mixture. But in preparations of blood of a chromic anemia stained with the same solution in which possibly all stages of the degeneration in question are present one sees red discs with a faint inclination to violate. Others which are bluish red and at the end of the series forms stained a fairly intense blue in which scarcely a trace of red can be seen and which by their peculiar notched periphery are evidently to be regarded as dying elements. Erlich put forward the theory that this remarkable behavior towards dies indicates a gradual death of the red blood corpuscles. That is of the old forms leading to a coagulation necrosis of the discoplasm. The latter takes up as is the case in coagulation necrosis the proteids of the blood and acquires thereby the power of combining with nuclear stains. At the same time the discoplasm loses its power of retaining the hemoglobin and gives it up to the blood plasma in ever increasing quantity as the change proceeds. Hence the disc continues to lose the capacity for the specific hemoglobin stain. Objection has been raised to these views from many quarters especially from Gaborczowski and afterwards from Askenazi, Dunin and others. The polychromatophil discs are not they say dying forms but on the contrary represent young individuals. The circumstance that in certain anemias the early stages of the nucleated red corpuscles are variously polychromatic was evidence for this opinion. In view of the great theoretical importance which attaches to the subject the grounds for regarding this change as degenerative may be here shortly brought forward. Number one the appearance of the erythrocytes which shoe polychromatophilia in the highest agree by the notching of their margins they appear to eyes practiced in the judgment of morphological conditions in a stage almost of dissolution and as well pronounced degeneration forms. Number two the fact that by animal experiment for instance in anion their appearance in large numbers in the blood can be produced that is precisely in conditions where there can be least question of a fresh production of red blood corpuscles. Number three the clinical experience that in acute losses of blood in man these staining anomalies can be observed in numerous cells within so short a time as the first 24 hours. Whilst in our observations which are very numerous upon this point embracing several hundred cases and carried out with particular care no nucleated red blood corpuscles in this space of time can be found in man. Number four the polychromatophil degeneration can frequently be observed in nucleated red blood corpuscles particularly in the megaloplasts. This fact can be so easily established that it can hardly escape even an unpracticed observer and it was sufficiently familiar to Erlich who first directed attention to these conditions. The fact that the normal blasts which are typical of normal regeneration are as a rule free from polychromatophil degeneration gave the key for the interpretation of this appearance and similarly for the nucleated red blood corpuscles of lower animals. Askenazi asserts that the nucleated red blood corpuscles of the bone marrow which he was able to investigate in a case of ampyema shoe immediately after the resection of the ribs complete polychromatophilia. This perhaps depends on the peculiarities of the case or on the uncertainty of the staining method. Eosin methylene blue stain which is for this purpose very unreliable since slight overstanding towards blue readily occurs. We expressly advise the use of the triacid solution or of the hematoxiline eosin mixture for the study of the anemic degeneration. After what has been adduced we hold in agreement with the recent work of Papenheim and Maragliano that the appearance of polychromatophilia is a sign of degeneration. To explain the presence of erythroblasts which have undergone these changes we must suppose that in severe entries to the life of the blood these elements are not produced in the usual fashion but from the very beginning are morbidly altered. Analogies from general pathology suggest themselves in sufficient number. B. A second change that we find in the red blood corpuscles of the anemias is pokylocytosis. By this name a change of the blood is denoted where along with normal red blood corpuscles larger smaller and minute red elements are found in greater or less number. The excessively large cells are found in pernicious anemia as Lach first observed and as has since been generally confirmed. On the contrary in all other severe or moderate anemic conditions the red corpuscles show a diminution in volume and in their amount of hemoglobin. This contradiction which Lach first mentioned but was unable to explain has found a satisfactory solution in Erlich's researches on the nucleated precursors of the myelocytes and normocytes, C. below. The blood picture of the anemias is made still more complicated in that the diminutive cells do not preserve their normal shape but assume the well-known irregular forms, pair, balloon, saucer, canoe shapes. Nevertheless, in good dry preparations the smallest forms usually still shoot the central depression. The so-called microsites constitute an exception to this statement. These are small round forms to which was allotted in the early days of the microscopic investigation of the blood a special significance for the severe anemias. They are however nothing but contraction forms of the poichelocytes as the granated are of the normal corpuscles. Consequently microsites are but seldom found in dried specimens whilst in wet preparations they are easily seen after some time. It is further of importance to know that in fresh blood the poichelocytes exhibit certain movements which have already given rise to mistakes in many ways. Thus at one time the poichelocytes were considered to be the cause of malaria. More recently the somewhat larger sizes were regarded by clubs, pearls, as amoebas and similar organisms. In agreement with Haim, who from the very first described these forms as pseudo-parasites, a warning must be given against attributing a parasitic character to them. The origin of poichelocytosis, previously the subject of much discussion, is now generally explained in Erlich's way. For the mere fact that by careful heating poichelocytosis can be experimentally produced in any blood forces one to the assumption that the poichelocytes are products of a fragmentation of the red blood corpuscles, schistocytes, Erlich. And correspondingly the smallest fragments show the biconcave form in the dry specimen for they too contain the specific protoplasm of the disc, quote, which possesses the inherent tendency to assume the typical biconcave form in a state of equilibrium, unquote. Qualitative changes in the protoplasm of the poichelocytes are not to be observed even by staining and one may therefore ascribe to them complete functional power and regard their production as a purposeful reaction to the diminished number of corpuscles. Over by the division of a larger blood corpuscle into a series of homologous smaller ones, the respiratory surface is considerably increased. C. A third morphological variation which anemic blood may shoe in the more severe degrees of the disease is the appearance of nucleated red blood corpuscles. Though we do not wish to enter here upon the latest questions concerning the origin of the blood elements, we must shortly indicate the present state of our knowledge of the nucleated red corpuscles. Since the fundamental work of Newman and Bezosero, the nucleated forms have been generally recognized as the young stages of the normal red blood corpuscles. Hayham's theory, on the contrary, obstinately asserts the origin of the erythrocytes from blood platelets and has, accepting by the originator and his pupils, been generally allowed to drop. Ehrlich had, in the year 1880, pointed out the clinical importance of the nucleated red blood corpuscles in as much as he demonstrated that in the so-called secondary anemias and in leukemia nucleated corpuscles of the normal size, normal blasts, in pernicious anemia, excessively large elements, megaloblasts, gigantoblasts are present. At the same time, Ehrlich mentioned that the megaloblasts also play a prominent part in embryonic blood formation. In 1883 Hayham, likewise, proposed a similar division of the nucleated red blood corpuscles into two. One, the globules nucleas geantes, which he found exclusively in the embryonic state. Two, the globules nucleas detail moen, which he found invariably present in the later stages of embryonic life, and in adults. Further, W. H. Howell, 1890, found in Katz embryos two kinds of erythrocytes. One, very large, equivalent to the blood cells of reptiles and amphibia, ancestor corpuscles. And two, of the usual size of the blood corpuscles of mammalia. And similar, more recent authors, H. F. Mueller, C. S. Engel, Papenheim, and others have adhered to the division of hematoblasts into normo and megaloblasts. And it is on the whole recognized that physiologically normal blasts are always present in the bone marrow of adults, as the precursors of the non-nucleated erythrocytes. That the megaloblasts, however, are never found there under normal circumstances, but only in embryonic stages, and in the first years of extrauterine life. S. S. Gnazzi, on the contrary, has expressed the view that the normo blasts may arise from the megaloblasts, and thereby denies the principal distinction between them. Shaman also holds that the separation of the two kinds rests on doubtful foundation, since occasionally it is questionable whether particular cells are the normo blasts or the megaloblasts. We distinguish three kinds of nucleated red blood corpuscles on the grounds of the following characters. 1. The normal blasts. These are red corpuscles of the size of the usual non-nucleated disc, whose protoplasm as a rule shows a pure hemoglobin color, and which possess a nucleus. Occasionally there may be two to four nuclei. The sharply defined nucleus lies generally in the center, comprises the greater part of the cell, and is above all distinguished by its intense color with nuclear stains, which exceeds that of the nuclei of the leukocytes, and indeed of all known nuclei. This property is so characteristic that the free nuclei, which occur occasionally in anemias and particularly often in leukemia, may be recognized as nuclei of normo blasts, although surrounded by traces only of hemoglobin, or by none at all. 2. The megaloblasts. These are two to four times as large as normal red blood corpuscles. Their protoplasm, which constitutes by far the chief portion of the body of the cell, very often shows anemic degeneration to a greater or less degree. The nucleus is larger than that of the normo blasts, but does not form so considerable a fraction of the cell as in the latter. It is often not sharply defined, and is of a rounded shape. It is distinguished from the nucleus of the normo blast by its much weaker affinity for nuclear stains, which may often be so small that little practiced observers perceive no nucleus. Occasionally very large cells are present of the kind just described, which are therefore called gigantoblasts, but which are not distinguishable in other respects from the megaloblasts. It cannot be denied that it is often difficult to decide whether a particular cell is to be regarded as especially small megaloblasts or a large normo blast. In such cases one would naturally search the preparation for perfect forms of hematoblasts and for the presence of free nuclei or of megalocytes in order to obtain an indirect conclusion concerning the cells in question. Three, the microblasts. These are occasionally present, e.g. in traumatic anemias, but they are very seldom found, and have not so far attracted particular attention. The question of the meaning of the normal blast and megaloblasts has led to lively and significant discussions partly in favor of, partly against, the distinction between these two cell forms. After surveying the literature, we are forced to separate the megaloblast from the normal blast in the first place because of their subsequent histories and the peculiarities of their nuclei, and secondly because of clinical observation. The fate of the nuclei for some time passed two views, almost diametrically opposed, have been in existence with regard to the nature of the change of the nucleated to the non-nucleated erythrocytes. The chief exponent of the one, Renfleisch, told that the nucleus of the erythroblasts leaves the cell, which thereby becomes a complete erythrocyte, whilst the nucleus itself, by the aid of the small remnant of protoplasm, which surrounds it, takes up new material from the surrounding plasma, manufactures hemoglobin, and so becomes a fresh erythroblast. According to the second theory, the erythroblasts change to non-nucleated discs by the destruction and solution of the nucleus within the cell body. Cariorhexes cariolisis. The authors who support this view, and also describe it as the only kind of erythrocyte formation, are chiefly Kolliker and E. Newman. Renfleisch arrived at his theory by direct observation of the process described, as it occurred in physiological saline solution with the blood of fetal guinea pigs, and teased preparations of bone marrow. E. Newman regards Renfleisch's doctrine as untenable, since the process which he observed is chiefly the result of a severe injury of the blood from the sodium chloride solution and the teasing. If a method of preparation be chosen which protects the blood as far as possible, and avoids every chemical and physical alteration, the exit of the nucleus as described by Renfleisch does not occur. The view of Kolliker and Newman that the nuclei gradually decay in the interior of the cell is not supported by the observation of a process, but by the fact that in suitable material, for instance, fetal bone marrow, liver blood, and leukemic blood, the transition from erythroblast to erythrocyte is shown by all phases of nuclear metamorphosis, versus Wrecklinghausen professes to have directly observed the dissolution of the nucleus within the cell in rabbits blood, kept living in a moist chamber. Pappenheim's opinion, however, that in this case processes are concerned such as Maragliano and Castellino have described as artificial necrobiosis seems in this connection worthy of consideration. Just as with regard to the formation of the erythrocytes, the views differ one from another, so also with regard to the free nuclei which come under observation in numerous preparations. Kolliker has taught that these nuclei are not quite free, but are always surrounded by a minute border of protoplasm. On the other hand, Rheinfleisch regards these nuclei as having migrated from or having been cast off by the erythroblasts, and Nomen explains them as early forms of erythroblasts. Erlich was the first two endeavor to affect a compromise between the directly opposed views of Rheinfleisch and Nomen. He taught that both kinds take part in the production of the red discs. From blood preparations which contain numerous normalblasts, for instance, in blood crises, see page 62, an unbroken series of pictures can easily be put together showing how the nucleus of the erythroblasts leaves the cell, and at last produces the appearance of the so-called free nucleus. It must be expressly mentioned that these pictures are only to be found in specimens in whose preparation pressure of any kind upon the blood has been avoided. Further, however rich a blood may be in normal blasts, the metamorphosis of the nucleus as described by Nomen is practically never to be observed. It is quite otherwise with the megaloblasts. Amongst them, few examples are to be found in which traces at least of the destruction and solution of the nucleus are not shown, and in a blood preparation of pernicious anemia, which is not too poor in megaloblasts, one can construct step-by-step the unbroken series from megaloblasts with a complete nucleus through all stages of cariorhexis and cariolisis to the megalocytes as the process is described by Nomen. From Erlich's observations it follows that the normal blasts become normal sites by extrusion or emigration of the nucleus. The megaloblasts become megalocytes by degeneration of the nucleus within the cell. M. B. Schmidt, without making use of the principal distinction made by Erlich, also concludes from his researches on sections of the bone marrow of animals in extrauterine life that both kinds of erythrocyte formation occur. Quite recently Papenheim, partly in conjunction with O. Israel, has carried out very thorough researches on these particular points. As the subject for observation he chose the blood of embryonic mice. He was able, in the first place, like Rheinflisch to produce the exit of the nuclei from the cells by the addition of physiological salt solution to fresh blood, and is of the opinion that the exit of the nucleus from the erythroblasts only takes place artificially. In embryonic blood the metamorphosis to erythrocytes occurs exclusively by nuclear destruction and solution within the cell, be it in the case of megalo- or gegantoblasts, or of cells of the size of the normal red blood corpuscle. The free nuclei that are observed whose appearance Papenheim explains by a proceeding solution of the protoplasm, plasmolysis, he regards in opposition to Rheinflisch and Newman, not as the beginnings of a developmental series, but as the surviving remnants of the degenerated dying blood cells. Clinical observation certainly does not support this conception of Papenheims in as much as in suitable cases with numerous free nuclei, leukemia, blood crises, transitional forms, which according to Papenheim must necessarily be present, are not to be found. Moreover, in alluding to a case of leukemia of this kind, this author himself admits that the appearance of free nuclei can be explained in this instance by the exit of the nucleus. Although Papenheim, as above mentioned, recognizes no difference between megaloblasts and normalblasts in embryonic blood as far as the fate of the nucleus is concerned, he nevertheless decidedly supports Erlich's separation of the erythroblasts into these two groups as two hematogenetically distinct species of cells. He does not regard as distinguishing characteristics the size and hemoglobin content of the cells, although as we have described above, these are in general different in normal and megaloblasts. For these two properties undergo such great variations as to increase considerably under certain circumstances the difficulty of diagnosis of individual cells. The chief characteristic is, as Erlich has always particularly insisted, the constitution of the nucleus. The nuclei of cells which are with certainty to be reckoned among the normalblasts are marked by the absence of structure, their sharply defined contour, their intense affinity for nuclear stains, that is by properties which histology sums up under the name Pynosis-Fitzner, and recognizes as signs of old age. The nuclei of the megaloblasts are round, show a good deal of structure, and stain far less deeply. Beta, the clinical differences. Normalblasts are found almost invariably in all severe anemias that are the result of trauma in anition or organic disease of some kind. They are, however, mostly rather scanty so that a preparation must be searched for some time before an example is found. But occasionally, most often in acute but also in chronic anemias and even in chachetic conditions, every field shows one or more normalblasts. V Norden was the first to describe a case in which in the course of a hemorrhagic anemia, normalblasts temporarily appeared in such overwhelming numbers in the circulating blood that the microscopic picture, which at the same time comprised a marked hyperlocosatosis, was almost similar to that of myologenous leukemia. And as in addition to this occurrence, the number of blood corpuscles was nearly doubled. V Norden gave it the distinctive name, blood crisis. The following procedure is to be recommended for the investigation of the blood crisis. 1. Estimation of the absolute number of red blood corpuscles. 2. Estimation of the proportion of white to red corpuscles. 3. Estimation of the proportion of nucleated red to white corpuscles by means of the quadratic ocular diaphragm, C-page 31, in the dry preparation. For instance, if we find in a case of anemia 3.5 millions of red blood corpuscles, the proportion of white to red corpuscles equal 1.100th and that of the nucleated red to the white equal 1.10th. Then in one cubic millimetre there are 3.500 nucleated red corpuscles. That is for 1,000 ordinary there is one nucleated corpuscle. Megaloplasts, on the contrary, are never found in traumatic anemias. And in chronic anemias of the severest degree, the result for example of old syphilis, carcinoma of the stomach, and so forth, one looks for them almost always in vain, although they are sometimes to be found in leukemia. On the contrary, the conditions apparently much milder, in which from the clinical history, etiology, and general objective symptoms, pernicious anemia is suggested, are almost without exception characterized by the appearance of megaloplasts in the blood. Nevertheless, in very late stages of the disease, they are always ganti, and a very tedious search through one or more specimens is often required to demonstrate their presence. Hence follows the rule that the investigation of a case of severe anemia should never be considered closed, before three or four preparations at least have been minutely searched for megaloplasts under an oil immersion objective. This clinical difference between the two kinds of hematoblasts admits of but one natural conclusion, which primarily leaves untouched the question, so much discussed at the present time, whether the megalo or normal blasts can change one to the other. In all cases of anemia, in which the fresh formation occurs according to the normal type, only in greater quantity and more energetically, we find normal blasts. Almost all anemias resulting from known causes, acute hemorrhages, chronic hemorrhages, poverty of blood from inination, caeccias, blood poisons, hemoglobinemia, and so forth, in short, all conditions rightly called secondary symptomatic anemias, make sure this increase of normal blood production. In the conditions which Behrmer, on the grounds of their clinical peculiarities, has distinguished as, quote, essential pernicious anemia, unquote, megaloplasts, on the contrary, occur and represent an embryonic type of development. The extent to which this type participates in the blood formation in pernicious anemia is most simply demonstrated by the fact that megaloplasts are present in all cases of pernicious anemia, as luck first should, and in some cases form the preponderating portion of the blood discs. Whilst, therefore, in the ordinary kinds of anemia, we find that the red corpuscles tend to produce small forms in pernicious anemia, on the other hand, and exclusively in this form we find a tendency in the opposite direction. This constant difference cannot be a chance result, but must depend on some constant law. In pernicious anemia, excessively large blood corpuscles are produced. Erlich's demonstration of megaloplasts has suffice for this logical advance. All researches, which try to obscure or totally deny the distinction between megaloplasts and normoplasts, are wrecked by the simple clinical fact that in pernicious anemia the blood is megaloplastic. The appearance of megaloplasts and megalocytes is therefore evidence that the regeneration of the blood in the bone marrow is not proceeding in the normal manner, but in a way which approximates to the embryonic type. The extreme cases are naturally seldom, such as that of rindflesh, in which the whole bone marrow was found full of megaloplasts. It is sufficiently conclusive for the pernicious nature of the case. Quote, if only considerable portions, but not the whole marrow, have lapsed into megaloplastic degeneration. We can now say that the megaloplastic metamorphosis is not a purposeful process, and for the following reasons. One, since the fresh formation of red blood corpuscles by means of the megaloplastic method is clearly much slower. This is especially borne out by the fact that the megaloplasts are present in the blood, always in small numbers only, while the normal blasts, as above mentioned, are often found in much larger quantities. In agreement with this, blood crises are not to be observed in the megaloplastic anemias. Two, since the megalocytes, which are formed from the megaloplasts, possess in proportion to their volume a relatively smaller respiratory surface, and so constitute a type disadvantageous for anemic conditions. This is still more evident when we remember that the production of pokelocytes is, on the contrary, a serviceable process. The megaloplastic degeneration of the bone marrow is no doubt due to chemical influences, which alter the type of regeneration in a disadvantageous manner. We do not, for the most part, yet know the exciting causes of the toxic process. Consequently, we are unable to put a stop to it, and its termination is lethal. The Bothreocephalus anemias, which in general, as is well known, offer a good prognosis, by no means contradict this view. They hold their privileged position amongst the anemias of the megaloplastic type, only for the reason that their cause is none to us, and can be removed. As in many infectious diseases, individuals react quite differently to the presence of the Bothreocephalus. Some remain well, others show the signs of simple anemia, ultimately with normal blasts, while a third group presents the typical picture of pernicious anemia. For many years, so long as its etiology was unknown, Bothreocephalus anemia was not separated on clinical grounds from pernicious anemia. Severe Bothreocephalus anemia may be described as a pernicious anemia with a known and removable cause. Good evidence for this point of view is afforded by a case of Eskenazi, who describes a severe pernicious anemia with typical megaloplasts, in which after the complete expulsion of the Bothreocephalus, the megaloplastic character, the blood formation quickly vanished, was replaced by the normal blastic, and the patient rapidly recovered. This observation is so unequivocal that it is a matter of surprise that Eskenazi chooses to deduce from it the ready transition from megaloplast to normal blasts, whereas it is clear and definite evidence that megaloplasts are only produced under the influence of a specific intoxication. And in this way the presence of megaloplasts in the pernicious anemias is to be explained. The megaloplastic degeneration of the bone marrow depends on the presence of certain injurious influences, of which unfortunately we are as yet ignorant. Were it possible to remove them it is quite certain, a priority, that the bone marrow, if the disease were not too advanced, would resume its normal blastic type of regeneration. Clinical observation supports this contention in many cases. In megaloplastic anemias apparent cures are by no means rare, but sooner or later a relapse occurs and finally leads with certainty to a lethal issue. These cases, familiar to every observer, prove with certainty that the megaloplastic degeneration as such may pass away, and that in isolated cases the conventional treatment by arsenic suffices to bring about this result. A definite cure, however, under these conditions is not yet attained, since we do not know the etiological agent. Still less can we remove it. For this reason, the prognosis of megaloplastic anemia, apart from the group of bothereocephalus anemia, is exceedingly bad. Section 5 of Histology of the Blood. Histology of the Blood by Paul Ehrlich and Adolf Lazarus. Section 5 of Histology of the Blood. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org, recording by Peter Yersley. Histology of the Blood by Paul Ehrlich and Adolf Lazarus. Translated by Emma Meyers. Section 5, The White Blood Corpuscles. The physiological importance of the white blood corpuscles is so many-sided that they form the most interesting chapter of the subject, that the white blood corpuscles play a significant part in the physiology and pathology of man has been recognised, but slowly, obviously because there was at first some hesitancy in ascribing important functions to elements that are present in the blood in such relatively small numbers. A place in pathology was first assured to them by Virchow's discovery of leukemia. The interest in the question was increased by Cohnheim's discovery that inflammation and supuration are due to an emigration of the white blood corpuscles, and these conditions were particularly suitable for throwing light on normal processes. The fact that in diffuse inflammations large quantities of pus are often produced in a short time, without the blood being thereby made poorer in leukocytes, that the opposite indeed occurs, necessitated the supposition that the source of the leukocytes must be extraordinarily productive. Hence, in contradistinction to the red blood corpuscles, their small number is fully compensated by their exceptional power of regeneration. Nevertheless, a considerable time elapsed before the powerful impulse that started from Cohnheim, or fruit for clinical histology. As we have mentioned, this was due to the circumstance that an exact differentiation of the various forms of leukocytes was very difficult with the methods in use up to that time. Although such distinguished observers as Wharton-Jones and Max Schultz had been able to distinguish different types of leukocytes, Cohnheim's work remained clinically fruitless since the criteria they assigned were far too subtle for investigation at the bedside. The discovery of leukocytosis interpreted it as an increase of the lymphocytes, whereas it is chiefly produced by the polynuclear cells. Only after the distinction was facilitated by the dry preparation and the use of stains did interest in the white corpuscles increase and continue progressively to the present day. This is borne out by the exceptionally exhaustive hematological literature, and particularly by that of leukocytosis. In spite of these advances, a retrograde movement in the doctrine of the leukocytes has gained ground surprisingly, especially in the last few years. Ever since Virtua's description of the lymphocytes, observers have tried to separate the various forms of leukocytes one from another, and if possible to assign different places of origin to these different kinds. There now suddenly appears an endeavour to bring all the white blood corpuscles into one class, and to regard the different forms as different stages merely of the same kind of cells, the following sections will show that this tendency is unwarranted and unpractical. One. Normal and pathological histology of the white blood corpuscles. The classification of the white corpuscles of normal human blood, drawn up by Ehrlich, has been accepted by most authors, and we therefore give a short summary of it, as found it on the dry specimen. One. The lymphocytes. These are small cells, as a rule approximating in size to the red blood corpuscles. Their body is occupied by a large round, homogeniously stained nucleus, centrally situated, whilst the protoblasms surround the nucleus as a concentric border. Between nucleus and protoblasm there is often found a narrow areola, which doubtless results from artificial retraction. Nucleus and protoblasm are basophil, nevertheless in many methods of staining the protoblasm possesses a much stronger affinity for the basic stain than does the nucleus. The nucleus in these cases stands out as a bright spot from the deeply stained mass of protoblasm, which is reticulated in a peculiar manner. Within the nucleus are often to be found one or two nucleoli, with a relatively thick and deeply stained membrane. With methylene blue and similar dyes the protoblasm stains unequally, which is not to be considered as the expression of a granulation, as Ehrlich first assumed, but rather of a reticular structure. The contour of the lymphocytes is not quite smooth as a rule, at least in the larger forms, but is somewhat frayed, jagged and uneven. Small portions of the peripheral substance may repeatedly bud off, especially in the large forms, and circulate in the blood as free elements. In stained specimens, especially from lymphatic leukemia, these forms, which completely resemble the protoblasm of the lymphocytes in their staining, may from their nature and origin be readily recognised. As far as the further metamorphosis of the nucleus is concerned, a sharp notching of the border of the nucleus may occasionally be found, the further fate of which is shown in the accompanying figure. It is evidence that in this case the resulting nuclear forms are quite different from those which are characteristic of the polynuclear elements. The protoblasm possesses no special affinity for acid and neutral dyes, and hence in triacid and hematoxilin preparations. The small lymphocytes are seen chiefly as lightly stained nuclei, apparently free. In the larger cells the protoblasm can be seen even in these preparations to be slightly stained. By the aid of the iodine eosin method, the reaction of the protoblasm of the lymphocytes is shown to be strongly alkaline. They do not contain glycogen. These properties, taken as a whole, constitute a picture completely characteristic of the lymphocytes, and these elements can thereby be diagnosed and separated from other forms, even when their size varies. Generally speaking, these cells, as above mentioned, are distinguished in the blood of the healthy adult by their small size, approximating to that of the red blood corpuscles. In the blood of children, on the contrary, larger forms are found even in health, and in lymphatic leukemia, particularly large forms occur, which are mistaken in various ways by unpracticed observers. Thus Trojus' marrow cells still figure in the literature, but have absolutely nothing to do with the marrow. They are large lymphocytes, as was established by A. Frankel years afterwards. In the normal blood of adults, the number of the lymphocytes amounts to about 22 to 25 percent of the colorless elements. Increase of the lymphocytes alone occurs, but in comparison with that of the other forms, much more seldom, and will be conveniently called by the special names of lymphocytosis or lymphemia. 2. Sharply to be distinguished from the lymphocytes is the second group, the large mononuclear leukocytes. These are large cells about twice to three times the size of the erythrocytes.  The latter is free from granulations, feebly basophil, and in contrast to the protoplasm of the lymphocytes, stains less deeply than the nucleus. This group is present in normal blood in but small numbers, about one percent. They are separated from the lymphocytes because they are totally different in appearance, and because forms transitional between the two are not observed. It cannot yet be decided from which blood-producing organs these forms arise, whether from spleen or bone marrow, although there are many reasons for regarding the latter as their place of origin. These large mononuclear leukocytes change in the blood to the following three, the transitional forms. These resemble the preceding, but are distinguished therefrom by deep notchings of the nucleus, which often give it an hourglass shape, further by a somewhat greater affinity of the nucleus for stains, and by the presence of scanty-neutrophil granulations in the protoplasm. The groups, two and three, comprise together about two to four percent of the white blood corpuscles. Footnote, in enumerating the blood corpuscles, two and three may be counted separately or in one group. End footnote. Four, the so-called polynuclear leukocytes. These arise in small part, as will be described later in detail, from the above mentioned number three, within the bloodstream. By far the largest part is produced fully formed in the bone marrow, and emigrate to the blood. These cells are rather smaller than numbers three and two, and are distinguished by the following peculiarities. Firstly, by a peculiar polymorphous form of nucleus, which gives the relatively long irregularly bulged and indented nuclear rod the appearance of an S, Y, E or Z. The complete decomposition of this nuclear rod into three to four small round single nuclei may occur during life as a natural process. Erlich first discovered it in a case of hemorrhagic smallpox. It is frequently found in fresh exudations. Formerly, when various reagents, for instance acetic acid, were customarily used, the decomposition of the nucleus into several parts was more frequently observed, and Erlich for this reason chose the not wholly appropriate name polynuclear for this form of cell. As this name has now been universally adopted and misunderstandings cannot be expected, it is undoubtedly better to keep to it. The expression cells with polymorphous nuclei would be more accurate. The nucleus stains very deeply with all dyes. The protoplasm possesses a strong attraction for most acid stains and is unmistakably characterized by the presence of a dense neutrophil granulation. The reaction of the protoplasm is alkaline, to a lesser degree, however, than in the lymphocytes. No free glycogen is contained in the polynuclear cells as a rule. Nevertheless, in certain diseases cells are always found which give a marked iodine reaction. In this manner the appearance of cells containing glycogen in diabetes was first proved. Note Erlich, Gabrituschi, Liverato, end note. The iodine reaction in the white blood corpuscles is also seen in severe contusions and fractures, in pneumonias, in rapidly progressing phlegmata from streptococcus and stephalococcus, after protracted narcosis. Note Goldberger and the device. End note. Erlich explains the appearance of glycogen as follows. The glycogen is not present in the cell as such, but in the form of a compound which does not stain with iodine. This compound readily splits off glycogen, which then gives the iodine reaction. Foot note. The assumption of Zerny that the cells which react to iodine emigrate from suppurating foci is without foundation. A simple investigation of freshly inflamed tissue is sufficient to show that the cells which have wandered from the bloodstream soon contain glycogen. End foot note. We cannot regard the perinuclear green granules described by NIRSA in the polynuclear cells as pre-existing. The number of polynuclear leukocytes in the blood of the healthy adult amounts to about 70 to 72% of the total white corpuscles. Note Einhorn. End note. Foot note. Cantac described this group as finally granular oxyfill cells. Their granules stain red in eosin and in eosin methylene blue solutions, but the color is different from that of the true eosinophil cells and much less intense. In the latter mixture they stain really with the methylene blue salt of eosin. Their true nature is shown by their behavior with the triacid solution. End foot note. Five. The eosinophil cells. These are characterized by a coarse round granulation staining deeply with acid dyes and similar in other respects to the polynuclear neutrophils. With faint staining a thin peripheral layer of the eosinophil granule is seen more deeply stained than the interior. The nucleus as a rule is not so deeply stained as in the polynuclear neutrophil but otherwise in its general shape is completely similar. Both forms have in common a considerable contractility which renders possible their emigration from the vessels and their appearance in exudations and in pus. The size of the eosinophils frequently exceeds that of the neutrophils. Their number is normally about 2 to 4 percent of the white cells. Six. The mast cells. These are present though very sparingly in every normal blood. 0.5 percent is their maximum number in health. Their intensely basophil granulation of very irregular size and unequal distribution must specially be mentioned. The granulation possesses the further peculiarity in that with the majority of basic dyes it stains not in the pure color of the dye but metachromatically most deeply with thionine. As Dr. Morgan Roth found the deviation from the color of the dye is still more marked with Crecylviolet R. Mülheim Manufactory when the granules stain almost a pure brown. The staining power of the nuclei is very small and it is therefore hard to make out the shape of the nucleus without the use of difficult methods. In triacid preparations the granulation is unstained and the mast cells appear as clear poly nuclear cells free from granules. So much for the colorless cells in the blood of the normal adult. In pathological cases not only do the forms so far mentioned occur in altered numbers but abnormal cells also make their appearance. To these belong 1. Mononuclear cells with neutrophil granulation. Note myelocytes ehrlich endnote. Generally they are bulky with a relatively large faintly staining nucleus often fairly centrally placed and equally surrounded by protoplasm on all sides. A fundamental distinction from the large mononuclear cells lies in the fact that the protoplasm exhibits a more or less numerous neutrophil granulation. Besides the larger myelocytes much smaller forms approximating to the size of the erythrocytes are also found. All transitions between these two stages are likewise met with. In contradistinction to the polynuclear neutrophil elements these mononuclear forms show no amoeboid movement on the warm stage. They form a constant characteristic of myelogenic leukemia and in these cases generally occur in large numbers. Reinbach has found them in a case of lymphosarcoma with metastasis in the bone marrow. A. Lazarus observed their transitory occurrence in moderate number in a severe post hemorrhagic anemia. M. Beck observed them in the blood of a patient with severe mercury poisoning. They are also frequently found in children's diseases especially in anemia Pseudo leukemia in phantom. K. Elza established their presence in a boy of 15 months suffering from a slowly progressing tuberculosis of the lymphatic glands. The appearance of myelocytes in infectious diseases is particularly interesting. Rider had previously demonstrated that myelocytes may be present in acute inflammatory leukocytosis and recently a thorough work by CS Engel has appeared upon the occurrence of myelocytes in diphtheria. Engel discovered the interesting fact that myelocytes are often to be found in children suffering from diphtheria and further made the important observation that a high percentage of myelocytes, note 3.6 to 16.4% of the white elements, end note, only occurs in severe cases and points to an unfavorable prognosis. Myelocytes are also present in mild cases though not constantly and in much smaller number. Turk has recently undertaken a very exact and thorough analysis of their occurrence in infectious diseases in the course of which he accurately tabulated the white corpuscles in a large number of cases. The results he obtained in pneumonia are especially characteristic for he found at the commencement of the disease that myelocytes are not seen at all or only very scantily and it is only at the time of the crisis or directly afterwards that they become especially numerous. In isolated cases the increase at this time was very considerable and in one case amounted almost to 12% of all neutrophil cells. 2. Mononuclear eosinophil cells, note eosinophil myelocytes, end note, HF muhler was the first to point out their importance. They constitute the eosinophil analogue of the previous group and are much larger than the polynuclear eosinophils. Medium and small sized examples are often found in leukemia. Eosinophil myelocytes are almost constantly present in myelogenous leukemia and in anemia pseudolymphatica infantum. Apart from these two diseases they are very rarely found. Mendel saw them for example in a case of myxidema, Turk quite exceptionally in some infectious diseases. 3. Small neutrophil pseudolymphocytes. They are about as large as the small lymphocytes. Possess a rounded deeply stained nucleus and a small shell of protoplasm studied with a neutrophil granulation. The relatively deep stain of the nucleus and the small share of the protoplasm in the total cell body prevent confusion with the small forms of myelocytes which never reach such small dimensions. The neutrophil pseudolymphocytes are exceedingly infrequent and represent products of division of the polynuclear cells. They were first described by Erlich in a case of hemorrhagic smallpox. The process of division goes on in the blood in such a manner that the nuclear rod first divides up into two to four single nuclei and then the whole cell splits up into as many fragments. These cells occur also in fresh pleuritic exudations. After a time the nucleus of these cells becomes free and the little masses of protoplasm thus cut off are taken up mostly by the spleen substance. The free nucleus likewise shares in the destruction. It is of the greatest importance that these cells which up to the present have not elsewhere been described should receive more attention. They must be of significance in particular for the question of transitory hypolucosatosis which is by some referred to as a destruction by others to an altered localization of the white blood corpuscles. Four stimulation forms were first described by Turk and are mononuclear non-granulated cells. They possess a protoplasm staining with various degrees of intensity but in any case giving with triacid solution an extraordinarily deep dark brown and further a round simple nucleus often eccentrically situated stained a moderately deep bluish green with however a distinct chromatin network. The smallest forms stand between the lymphocytes and the large mononuclear leukocytes but approach the first named as a whole in their size and general appearance. According to Turk's investigations these cells often appear simultaneously with and under the same conditions as the myelocytes. Their importance cannot at present be accurately gauged possibly they form an early stage of development of the nucleated red blood corpuscles as the deeply staining and homogeneous protoplasm seems to indicate. With the description of these abnormal forms of white corpuscles all occurring forms are by no means exhausted. We are here accepting completely the variations in size which particularly affect the poly nuclear and eosinophil cells and which lead to dwarf and giant forms of them. For however considerable the difference in size these cells always possess characteristics sufficient for an exact diagnosis but besides these isolated cells of an especially large kind are found particularly in leukemic blood and concerning their importance and relationship we are up to the present in the dark. On the places of origin of the white blood corpuscles for the comprehension of the histology of the blood as a whole it is a great importance to obtain an exact knowledge how and to what extent the three organs which are undoubtedly very closely connected with the blood lymphatic glands bone marrow and spleen contribute to its formation. The most direct way of deciding the question experimentally by excision of the organs in question is unfortunately only available for the spleen. The part played by the lymphatic glands and bone marrow whose exclusion in Toto is not possible must mainly be determined by anatomical and clinical considerations but only by a careful combination of experiments on animals of anatomical investigations and especially of clinical observations on a large scale can like to be thrown on these very difficult questions. It's cannot be emphasized sufficiently how important it is that everyone engaging in hematological work should first of all collect a large series of general observations otherwise errors are bound to occur. For instance the endeavor is often made to compensate the lack of personal experience by careful literary studies but in this way the histology of the blood falls into a vicious circle of which the new phase of blood histology affords many examples and it is characteristic of this kind of work that from the investigation of a single rare case most far-reaching conclusions on the general pathology of the blood are at once drawn, e.g. Troja's paper in which having failed to recognize the lymphocytic character of a case of leukemia and believing therefore that he had to do with a myelogenous leukemia the author denied and completely reversed all that had been previously established about this disease. It is equally hard to avoid errors if one confines oneself exclusively to animal experiments without supplementing these by clinical experience as is shown by the numerous papers of Uskoff not the anatomist not the physiologist but only the clinician is in the position to discuss these problems. In the introduction to this chapter we have already alluded to the striking retrograde movement in hematology at the present time brought about by the view that the white corpuscles as a whole are derived from the lymphocytes. If we disregard the embryological investigations on this point note Saksa end note anatomists physiologists and clinicians alike have taken up a similar point of view among anatomical papers we may refer to those of Guland according to whom all varieties of leukocytes are but different stages of development of one and the same element. He distinguishes hyaline, acidifil and basefil cells and derives all from the lymphocytes. Arnold advocates similar views though in a negative form he says that a distinction between so-called lymphocytes and the leukocytes with polymorphous nuclei on the grounds of the form of the cell and nature of the nucleus is not possible at the present time neither is a classification based on the granules admissible since the same granules occur in different cells and different granules in the same cell. The work of Guland and Arnold takes into consideration the differential staining of the granules in various ways. In spite of their facts we disagree with their conclusions and we shall therefore have to analyze them in the special description of the granulated cells and granules. Recently since 1889 Uskov has in particular published experimental work in this province of hematology. This has led him to see in the white blood corpuscles the developmental series of one kind of cell and to distinguish in it three stages one young cells which corresponds to our lymphocytes two ripe cells note globule mur end note large cells with fairly large and irregularly shaped nucleus which are therefore our large mononuclear and transitional forms three old cells note globule vir end note which represent our polynuclear cells the eosinophil cells are completely excluded from this classification amongst clinicians a Frankel has recently gone in the same direction and on the grounds of his experience in acute leukemias has supported the view of Uskov that the lymphocytes are to be regarded as young cells and early stages of the other leukocytes but few authors note for instance C. S. Engel ribbert end note have raised a protest to this mixing of all cell forms of the blood and have held to the old classification of Ehrlich but as it is emphatically taught in numerous medical works that all these cells are closely related the grounds for sharply separating the lymphocytes from the bone marrow group may here be shortly summarized and stress laid on the great importance which this apparently purely theoretical question has for clinical observation we shall come to most important conclusions about this point when we consider more closely the share which the various regions of the hematopoietic system take in the formation of the blood and especially of the colorless elements alpha the spleen the question whether the spleen produces white blood corpuscles has played a large part from the earliest times of hematology endeavors were first made to investigate the participation of the spleen in the formation of the white blood corpuscles by counting the white blood corpuscles in the afferent and efferent vessels of the spleen it was thought that the blood forming power of the spleen was proved by the larger number of corpuscles in the vein as compared with the artery the results of these enumerations however are very varying the investigators who found a relative increase in the vein are opposed by other investigators equally reliable and with the experience of the present day one would not lay any value on these experiments we must emphasize the fact established by later researches that after extirpation of the spleen an enlargement of various lymphatic glands occurs the alterations of the thyroid which have been observed by many authors cannot be described as constant further the blood investigations which mosler robin winogradow zersas and others have carried on in animals and man after removal of the spleen must here be mentioned these have already proved that a leukocytosis occurs after some considerable time professor kerloff carried out detailed investigations in 1888 in earlicks laboratory and carefully studied the condition of the blood after extirpation of the spleen as the work of professor kerloff has so far only appeared in russian his important results may be here recorded more fully for his researches kerloff employed the guinea pig as this animal by its peculiar blood is specially suited for this purpose in order to give a systematic account of the results of these important investigations we must first shortly sketch the normal histology of the blood of the guinea pig according to kerloff in the blood of the healthy guinea pig the following elements are found one cells bearing granules one polynuclea with pseudo ear cinephil granulation this granulation which alec had previously found in the rabbit is easily distinguishable from the true ear cinephil since it is much finer and stains quite differently in the earcine or antionigrosine mixtures one principle distinction between these two forms of cells lies in the fact that according to kerloff this granulation is very easily dissolved by acid but remains unchanged in alkaline solutions doubtless an indication that the granulation consists of a basic body soluble with difficulty which with acids forms soluble salts the true ear cinephil granulation remains on the other hand quite unchanged under these conditions these pseudo ear cinephil polynuclea cells correspond functionally to the neutrophil polynuclea of man their number amounts to 40 to 50 percent of the total white cells the red bone marrow is to be regarded as the place of origin of this kind of cell it contains very many pseudo ear cinephil cells and indeed all stages are to be found in it from the mononuclear cells bearing granules to the fully formed polynuclea two the typical ear cinephil leukocytes which fully correspond to those found in man and amount to about 10 percent of the number of the white three the nigrosinephil cells as they are called by kerloff in their general appearance in the size of the cell and the granulation they completely correspond to the ear cinephil cell the only distinction between them consists in a chemical difference in the granulation these cells stain in the color of nigrosine in the orantia earcin nigrosine mixture whilst the ear cinephil cells become red the two granulations always show different shades in the triacid preparation as well for the nigrosinephil cells stain a blacker hue two cells free from granules alpha cells with vacuoles this is a quite peculiar group characteristic for the blood of the guinea pig it shows transitions in the blood from large mononuclear to transitional and polynuclea forms but is marked by the lack of any kind of granulation instead of the latter we find in these cells a roundish nucleus like form in the protoblasm which also takes on the nuclear stains and possibly is to be considered an accessory nucleus we have received the impression that we have here to deal with a vacuole filled with substance secreted by the cell in a large series of preparations it is possible to obtain some elucidation of the development and fate of these appearances they first appear as point like granules in the protoblasm bearing no relation to the cell nucleus they gradually increase and acquire a considerable circumference when they have attained about the size of the cell nucleus they or rather their contents appear to break through the protoblasmic membrane and to leave the cell the number of the vacuole containing cells is 15 to 20 percent of the colorless blood corpuscles beta typical lymphocytes their appearance completely corresponds with that of human lymphocytes as described above they make up 30 to 35 percent of the total number of leukocytes now kerloff in the course of extremely careful and laborious researches estimated the total number of leukocytes and then from the percentage numbers the total quantity of pseudo eosinophil, neutrophil, eosinophil, vacuole containing cells and lymphocytes and could thus demonstrate that in uncomplicated cases of removal of the spleen where inflammatory processes accompanied by an increase of the polynuclear neutrophil corpuscles were avoided a gradual increase of the lymphocytes alone in course of time results this may be a two or three-fold increase whereas the numbers of all other elements remain unchanged kerloff obtained his figures as follows first he estimated the relative proportions of the different kinds of white blood corpuscles one to another in a large number of cells five hundred to a thousand a count of this kind however gives no evidence as to whether one or other kind of cell is absolutely increased or diminished a fall in the percentage of the lymph cells may be brought about by two quite different factors one by a diminished production of lymphocytes two by an increased influx of polynuclear forms which naturally lowers the relative count of the lymphocytes it was therefore necessary to obtain a method which would show alterations in the absolute number of the individual forms of leukocytes kerloff used for this purpose the comparative field that is he counted by the aid of a movable stage the different forms which lay on a definite area 22 square millimeters of the dried blood preparation this procedure gave very exact results as only faultlessly prepared and regularly spread preparations were used the following figures from experiment two illustrate the method and its results april the 12th 52 pseudo eosinophils september the second one month after the operation 22 pseudo eosinophils april the 12th 10 lymphocytes counted september the second 53 lymphocytes counted by the end of the comparative surface these figures were supplemented by the following averages on each surface used for comparison were found april the 12th 38 white consisting of 19.8 pseudo eosinophils 10.6 lymphocytes september the second 81 white consisting of 18.0 pseudo eosinophils 46.9 lymphocytes from this example it follows without doubt that the total number of the white blood corpuscles had about doubled itself but that in this increase the lymphocytes exclusively were concerned and the pseudo eosinophil cells had not undergone the smallest increase the results which kerloff obtained by means of this method in animals whose spleens had been removed may be illustrated by one of his original researchers and its accompanying chart and table experiment one young female weight 234 grams number of red corpuscles in a cubic millimeter of blood 5,780,000 number of white 10,700 on april the 19th 1888 the spleen was removed the wound healed by first intention the results of the further investigation of the blood are found in the following table from the chart and table the number on the surface of comparison of the white blood corpuscles is seen to have more than doubled itself in the first seven months and that this increase was solely dependent on the flooding of the blood by lymphocytes the nucleated or bone marrow elements and the large mononuclear cells remained continuously at the same level during the whole period the changes in the percentage proportions ran somewhat differently the percentages rose from 35 to 66 percent for the lymphocytes only whilst for the other forms they distinctly fell for the nucleated from 44 percent to 22 percent and for the large mononuclear from 18 percent to 9 percent it was only in the course of the second year that a very considerable relative and absolute increase of the eosinophil cells appeared the values rose gradually from about 1 percent to 28.9 percent or from 0.5 to 13.9 on each comparison area the last examination of the blood in this animal was made on april the 30th 1890 that is two years after the removal of the spleen the animal was quite healthy bore four healthy young guinea pigs by a father whose spleen had been removed the young have a completely normal spleen and their blood likewise shows no abnormalities reader's note table one showing cell numbers and proportions on 26 dates from april the 19th 1888 to april the 30th 1890 is omitted and reader's note the results of further investigations which we hear shortly repeat in tabular form show that in this experiment number one we are not dealing with an abnormal phenomenon of an exceptional animal experiment one before splenectomy 10 700 white blood corpuscles at the end of the first year 14 200 at the end of the second year 18 000 experiment two before splenectomy 12 000 white blood corpuscles at the end of the first year 27 600 at the end of the second year 32 000 experiment four before splenectomy 15 000 at the end of the first year 19 200 at the end of the second year 19 000 average before the splenectomy 12 600 at the end of the first year 20 333 at the end of the second year 23 300 by estimating the percentage proportion of the single kinds of white blood corpuscles curl off obtained the following result reader's note table omitted showing cell counts for five different cell types before operation at the end of the first year and at the end of the second year for three experiments and reader's note from these researchers we draw the following conclusions one the spleen is not an indispensable vitally important organ for the guinea pig since that animal bears splenectomy without loss of health develops normally and gains well in weight to the hypertrophy and hyperplasia of the lymph glands particularly of the mesenteric glands which develop after the operation correspond to a lymphocytosis which makes its appearance in the course of the first year after the operation so constantly that it may be looked upon as a characteristic sign of the absence of the spleen this increase may amount to double and more we must therefore assume that the deficiency of spleenic function may be met by the lymphatic glandula system this period of lymphemia may doubtless in some animals persist for years in exceptional cases in the majority however the lymphemia diminishes in the course of the first year and indeed subnormal quantities of lymphocytes may then be produced three the cells of the bone marrow on the contrary and the polynucleus sudo esonophil cells do not show the least variation in the course of the first year bearing in mind that under normal conditions these cells are met with exclusively in the bone marrow and that inflammation in animals after removal of the spleen is accompanied by an acute sudo esonophil leukocytosis exactly as in normal animals one must admit that the production and function of this kind of cell are quite independent of the spleen hence there can be no doubt about their myelogenic nature four it is especially important that the mononuclear and the leukocytes associated with them undergo no increase as these cells under normal circumstances occur both in the spleen and in the bone marrow we must assume that normally also the bone marrow is responsible for the majority of this kind in the blood and that the deficiency in the spleenic contribution can be easily covered by a slightly raised activity of the bone marrow where the share of the spleen important from general biological considerations and overproduction of the kind of selling question must occur in the vicarious organs five the increase of the esonophil cells which constantly makes its appearance in the second year after the operation is highly interesting and leads to a really enormous rise in their absolute and relative numbers their percentage number once rose to 34.6% and their absolute quantity amounted at the end of the second year on the average to 30 to 50 fold their original number hence it follows from Kerloff's research is that the spleen of the guinea pig plays quite an unimportant part in the formation of the white blood corpuscles and that after splenectomy in the first year compensation occurs only in the lymph glands followed in the second year by a great increase of the esonophil cells it is to be particularly insisted once again that the spleen has nothing at all to do with the formation of the pseudo esonophil polynuclear cells which are the analogues of the polynuclear neutrophils of man how do observations on man stand in the light of kerloff's observations which might be regarded as depending on peculiarities of the particular kind of animal completely analogous material is afforded by cases in which in healthy people a splenectomy has been necessary in consequence of trauma unfortunately the material available for this purpose is extremely rare and it would be of the utmost value if the alterations of the blood in such a case were systematically studied for a period of years we have ourselves begun our observations in two patients directly after the operation but were unable to continue them as death occurred within the first week after the extirpation up to the present only seven cases of rupture of the spleen with subsequent splenectomy have been published as is stated in the collection of cases of vbeck in two only of these seven cases one of rikers Breslau the other of vbeck's Karlsruhe was a cure affected through the courtesy of the above mentions gentleman we were able to investigate specimens from these two patients in the case of vbeck the operation was performed on june the 15th 1897 we received a dry blood preparation about six months after operation investigation showed a considerable lymphemia the bulk of the lymphocytes belonged to the larger kinds the eosinophil cells were certainly not increased for other reasons an exact numerical analysis could not be undertaken we hope to be able to follow the further course of this case in the second case the operation was performed on may the 17th 1892 by dr riker of Breslau for trauma and later described we made counts in oldish and fresh preparations it is worthy of notice that this case is not uncomplicated as an amputation of the thigh was performed shortly after the spleenectomy on a count of gangrene we found the following figures preparations from june the 12th 1892 polynuclear 81.9 percent october the 11th 1892 80.0 percent september 1897 56.8 percent lymphocytes from june the 12th 1892 15.9 percent october the 11th 1892 13.7 percent september 1897 33.1 percent eosinophil from june the 12th 1892 1.3 percent october the 11th 1892 4.0 percent september 1897 3.5 percent large mononuclear june the 12th 1892 no data october the 11th 1892 1.7 percent september 1897 1.5 percent it is much to be regretted that dry preparations only at the beginning and at the end of the five-year period of observation were at our disposal it appears from the paper of Riker as if in this case the lymphocytosis had established itself one months after the operation and had lasted for a very long time just as kerloff has found in some animal experiments just as little as a polynuclear increase is abnormal is an increase of the lymphocytes remarkable and in this case the lymphocytic increase was recognizable after the end of the fifth year the eosinophil cells oscillate at this period about the upper normal limit from all that we know it is probable that their number in the meantime had undergone an intercurrent increase the cases are more frequent in which a splenectomy has been undertaken on account of disease of the spleen amongst these the clearest results are a priori to be expected from spleen exists since the part of the spleen not affected by the cyst formation often shows quite a normal structure and therefore is physiologically active on the other hand the excision of chronic spleenic tumors may be for the blood condition of no importance in as much as the function of the spleen may have previously long been eliminated by pathological changes among these cases we must in the first place mention the well known and carefully investigated case of B. creda in a man 44 years of age the spleen was extirpated on account of a large spleen exist within two months of the operation they developed a thoroughly leukemic condition of the blood exclusively brought about by the increase of the lymphocytes as is seen from the results of creda and the table contained in his paper it is further remarkable that four weeks after the operation a painful doughy swelling of the whole thyroid appeared which remained with variations for nearly four months with the general recovery of the patient this shrank to a small remnant we notice further that this very interesting swelling of the thyroid which doubtless stands in the closest connection with the splenectomy is nevertheless no constant accompaniment of this operation as for instance in the case of v. beck where it was not present the most recent work on extirpation of the spleen for tumors is from Hartman and Vasquez as the result of their researches the authors arrive at the following conclusions one a slight post-operative increase of the red blood corpuscles and a true acute hyperleucocytosis occur and pass rapidly away two the hemoglobin equivalent of the corpuscles sinks at first but recovers its original value by degrees three four to eight weeks afterwards a lymphocytosis of varying duration is established four later after many months a moderate eosinophilia occurs we have ourselves been able to investigate three conclusive cases the first was a patient which we were ourselves enabled to investigate by the courtesy of dr. a newman the patient's spleen was removed by e-han on account of an echinococcus on february the fifth 1895 one may well assume that before the operation the spleen no longer discharged its normal function on september the second 1897 we found the following numerical proportions polynuclear neutrophil 76.5 percent lymphocytes 18.4 percent eosinophil 3.4 percent large mononuclear 1.1 percent mast cells 0.4 percent a condition therefore which was quite normal in this connection it must be mentioned that an incipient thesis pulmonum existed at the time to which we must attribute an increase of the polynuclear elements and without which the percentage figures of the lymphocytes and eosinophils would perhaps have been greater for the knowledge of the two other cases we are indebted to the kindness of professor dunescu of bucarest the one case was of a man of about 40 years of age in whom splenectomy was undertaken on september the 27th 1897 for an enlarged spleen healing by first intention the white blood corpuscles were permanently increased the proportion of whites to red was 1 to 120 to 1 to 130 the average number of red was 3 million our own examination of preparations obtained some two months after the operation showed a distinct lymphemia and also a preponderance of the larger lymph cells the eosinophil and mast cells were plainly increased we are unable to give more exact numerical data as the preparations sent to us were not spread with sufficient regularity from the second case which was also operated upon for enlargement of the spleen we unfortunately only obtained much damaged preparations nevertheless so much could with certainty be established that there was no considerable increase of the lymphocytes the eosinophils on the contrary were increased distinctly the mast cells to a lesser extent it is probable that the increase of both of the latter kinds of cell was not a consequence of the extirpation of the spleen alone but rather the expression of the reactive changes which had already begun before the operation from the exclusion of the spleenic function cases of splenectomy of this kind are transitional to the chronic diseases of the spleen the latter present great difficulties for one never knows how far in the most chronic diseases the other organs are damaged or influenced by the general illness an increase of the lymphocytes so long as an affection of the lymphatic glands may be excluded should be referred to functional exclusion of the spleen on the other hand an increase of eosinophil cells associated with the chronic tumor of the spleen is analogous to kerloff's secondary reaction of the bone marrow such cases are frequently found in the literature for instance moella and rider bring forth three cases of spleenic tumor caused by congenital syphilis cirrhosis of the liver near platinum in the cranial cavity and in which the numbers of the eosinophils amounted to 12.3 percent 7.0 percent 6.5 percent respectively in three cases of acute spleenic tumor in typhoid fever the figure 0.31 percent with a maximum of 0.82 percent was found these authors have already raised the question whether the increase of the eosinophil cells is connected with the spleenic tumor or the bone marrow perhaps the functional activity of the latter is vicariously raised to meet the more or less complete exclusion of the spleen from the formation of the blood since alec has distinctly asserted that the probable place of formation of the eosinophil cells is the bone marrow from what has been brought forward no doubt can now remain that the question has been decided quite in alec's favor but what then are the physiological functions of the spleen since that organ is unnecessary for the persistence of life doubtless its chief duty is the taking up of the greater part of the decaying fragments of red and white blood corpuscles in the bloodstream so that this valuable material is not quite lost for the organism thus ponfic has found that after destruction of the red corpuscles the spleen takes up a portion of their shadows and for this reason calls the spleenic tumor a a spodogenous spleenic tumor note greek spodos ruins end note alec has made a corresponding observation for the product of dissolution of the white blood corpuscles and has proved that the spleenic tumor which occurs in many infectious diseases and in phosphorus poisoning is to a large extent caused by the parenchyma of the spleen taking up the remains of the neutrophil protoplasm the question of the relation of the spleen to the fresh formation of red blood corpuscles is a problem of comparative anatomy observations on this point made on one kind of animal can certainly not claim validity for other kinds in lower vertebrates as in fishes frogs tortoises and also in birds the blood forming activity of the spleen is pronounced and of great importance in mammalia on the other hand in some cases this function cannot be demonstrated and in others only to a very small degree in the spleen of normal mice nucleated red blood corpuscles are seen in relatively large numbers in the rabbit they are less numerous and often only to be found with difficulty in the dog they only make their appearance after anemia from loss of blood normally they are absent in the human spleen nucleated red blood corpuscles are not to be found normally or in cases of severe anemia but exclusively in leukemic diseases you gabby in his recently published work on the hemolytic function of the spleen also emphasizes the difference between the various animal species in guinea pigs he found that the spleen acts largely as a scavenger of the red blood corpuscles in rabbits very slightly consequently after removal of the spleen in guinea pigs the number of red blood corpuscles rose 377 000 in the cubic millimeter and the amount of hemoglobin 8.2 percent after sploenectomy in rabbits the increase in these values is absent shortly summarizing our analysis of the facts before us we must say that the importance of the spleen for the production of the white blood corpuscles can in no respect be considerable and that if these cells really are produced by it they must be free from granulations the spleen therefore stands functionally in closer connection with the lymphatic gland system than with the bone marrow the spleen has not the least connection with ordinary leukocytosis footnote cs engel has recently proposed to call acute leukocytosis lianal leukocytosis in an analogy with the clinical idea of a lianal leukemia this terminology should only be used if the polynucleus cells did in fact arise from the spleen an assumption which engel himself does not once appear to make since he expressly warns against drawing any conclusion from this name as to their origin since however the acute leukocytosis as we shall show in the next section are exclusively to be referred to the bone marrow the term lianal leukocytosis seems to us quite mistaken for it must logically lead to a conception of the origin of the leukocytes exactly opposed to their actual relationships end footnote end of section six