consist  almost  entirely  of  the  minute  ramifications  of  these
vessels.  Among  them  are  some  small  bodies,  which  are  dis-
persed through  the  substance,  Hke  berries  on  a  bush :  these  are
asserted  also  to  be  composed  of  vessels.
The  tubular  part  certainly  proceeds  from  this  vascular
cortical  substance:  for  Ruysch,  and  after  him  several  other
injectors,  have  filled  these  tubes  with  injections  thrown  iuto  the
arteries.
The  tubuli,  of  which  this  part  is  composed,  seem  to  arise
obscurely  from  the  cortical  part.  They  soon  assume  somewhat
of  a  radiated  direction,  and  are  finally  arranged  so  as  to  form  the
papillae  or  cones  above  described.
On  these  papillse  or  cones  some  of  them  can  be  traced,  uniting
with  each  other,  to  form  larger  tubes,  which  terminate  on  the
surfaces  of  the  papillae,  in  orifices  large  enough  to  be  seen  dis-
tinctly. From  these  orifices  urine  may  be  forced  out  by  com-
pressing the  papillae.  On  this  account  the  tubes  have  been
called  tubuli  uriniferi.
— The  minute  round  bodies  (glomeruli)  which  are  distributed
like  berries  on  a  bush,  among  the  arteries  and  veins  of  the
cortical  portion,  and  are  visible  to  the  naked  eye,  are  called  the
corpuscles  or  acini  of  Malpighi.  These  bodies,  Malpighi  and
Schumlansky,  believed  to  be  hollow  sacs,  with  vessels  ramifying
on  the  parietes,  and  which  secreted  the  urine.  Ruysch,  Hewson,
and  more  recently  Huschke,  and  Miiller,  have  shown  that  they
are  formed  entirely  of  an  agglomeration  of  minute  vascular
branches  appended  to  the  minute  twigs  of  the  arteries,  and  are
mere  reservoirs  of  blood.  They  vary  from  the  j',^  to  the  ji,^  part
of  an  inch  in  diameter.
