SMVl  MATEKNi;  575

as  are  named,  respectively,  '  capillary,'  '  arterial,'  aad  'venous,'  is  con-
venient, and  probably  well  founded.  Tbe  most  frequent  examples  of
subcutaneous  nsevi,  and  the  more  frequent  superficial  nsevi,  wliicli  are
like  them  in  structure,  though  different  in  position,  are  such  as  may  be
called  '  capillary  ; '  understanding,  only  that  they  probably  affect  minute
arteries  and  veins  as  well  as  capillaries.  But,  on  the  one  hand
deviating  from  these  specimens,  we  find  that  in  some  cases  the  enlarge-
ment of  arteries  far  exceeds,  in  proportion,  that  of  the  veins  ;  the  swel-
lings pulsate,  and  are  florid  and  overwarm,  and,  if  injured,  throw  out
arterial  blood.  These  constitute  the  '  arterial '  form  of  the  disease  :  the
'  aneurism  by  anastomosis.'  And,  on  the  other  hand,  are  tumours
formed  mainly  of  dilated,  sacculated,  and  overgrowing  veins ;  to  these
arteries  of  comparatively  small  size  pass,  while  from  them  proceed  very
large  veins  :  and  they  are  subject  to  changes  of  size  in  all  the  events
that  affect,  not  the  arterial,  but  the  venous,'  part  of  the  circulation.
