He classified three types of papillae and distinguished between the horny and reticular layers of the tongue in his De lingua.  In his first book, which consisted of two letters sent to his friend Giovanni Borelli, he built on recent observations on 
He classified three types of papillae and distinguished between the horny and reticular layers of the tongue in his De lingua.  In his first book, which consisted of two letters sent to his friend Giovanni Borelli, he built on recent observations on Jean Pecquet to argue that hematosis, or the conversion of chyle to blood, doesn't occur in the liver but in the lungs.  His microscopic observation of a clot of coagulated blood led him to discover red corpuscles, as reported in his On Heart Polyps, while he discovered the aortic arches, the protoliver, and the glands of the prestomach in his work on embryology.  He discovered stomata in leaves, and produced a pioneering description of the silkworm moth, but is best known for his work on frogs, in which he made the first observations of the capillary system.  FTP, name this physician to Pope Innocent XII, an Italian biologist known for his namesake tubules in insects.
He classified three types of papillae and distinguished between the horny and reticular layers of the tongue in his De lingua.  
Marcello Malpighi