Am.  Jour.  Pharm. ) 
April,  1881.  j 
Sponges. 
183 
slime,  called  milk  by  Greek  fishermen.  This  investing  flesh  has  so  little 
resemblance  to  ordinary  animal  tissue  tliat  it  is  technically  called  "sar- 
code."  In  this  tissue  we  perceive  a  system  of  canals  or  pores,  which  run 
downward  in  all  directions  and  enter  directly  certain  little  cavities  or 
chambers  connected  with  circuitous  passages,  which  finally  lead  to  large 
outlets  or  "oscula."  The  pores,  belonging  only  to  the  flesh,  are  not  visible 
in  the  skeleton,  are  very  small,  yet,  compared  with  the  cells,  very  large. 
In  some  orders  of  sponge?  the  outer  walls  of  tlie  flesli  o])q\\  anywhere  and 
everywhere  for  the  admission  of  food,  and  no  well-defined  pores  are  visible, 
but  open  as  required. 
Fig.  1.— Sponge  (one-half  natural  size)  attached  to  rock. 
