258 
Bahama  Sponges. 
/  Am.  Jour.  Pharm- 
\       May,  1887. 
It  is  a  general  rule  that  a  reaction  effected  on  a  single  carbon  com- 
pound is  proportional  to,  or  in  direct  relation  to,  the  time,  especially 
if  the  action  is  of  the  nature  of  hydration.  The  divergence  from 
this  rule  observed  in  the  case  of  starch  and  water  indicates  that  starch 
granules  are  composed  of  a  complex  mixture  of  carbohydrates, 
and  not  only  of  one  or  two  compounds  (glanulose  and  amylose). 
Possibly  these  different  compounds  are  polymerides  of  one  original 
substance.  This  view  is  similar  to  that  held  by  many  physiologists 
concerning  the  different  layers  of  cellulose  which  constitute  cell- 
walls. 
BAHAMA  SPONGES. 
By  E.  M.  Holmes,  F.  L.  S., 
Curator  of  the  Museum  of  the  Pharmaceutical  Society. 
In  the  Bahama  Court  of  the  late  Colonial  and  Indian  Exhibition  a 
fine  series  of  the  different  commercial  varieties  of  West  India  sponges 
was  exhibited,  and  since  its  close  a  typical  specimen  of  each  of  them 
has  been  presented  to  the  Museum  of  the  Pharmaceutical  Society. 
During  the  last  few  years  sponges  have  formed  an  article  of  consid- 
erable import  from  the  Bahamas  to  this  country,  and  a  description  of 
the  different  kinds  met  with  in  commerce  may  therefore  be  found 
useful  for  reference.  In  order  to  make  clear  the  features  in  which 
the  several  commercial  varieties  differ,  it  will  be  necessary  to  refer 
briefly  to  the  structure  of  these  animals  in  a  living  state. 
By  zoologists  sponges  are  classed  as  an  order  of  the  sub-kingdom 
Protozoa,  the  leading  feature  of  which  is  that  the  animals  included  in 
the  order  consist  of  a  composite  mass  or  colony  of  small  amoeboid  par- 
ticles of  gelatinous  matter,  supported  by  a  skeleton,  which  consists 
either  of  a  network  of  horny  fibres  or  of  calcareous  or  silicious  spi- 
cules, f 
Consequently  in  the  fresh  state  sponges  present  an  appearance  ex- 
ceedingly different  to  that  with  which  we  are  familiar,  forming  dark, 
unsightly  masses  of  jelly,  and  it  is  only  when  the  sarcode  or  gelati- 
nous matter  is  removed  that  the  skeleton,  known  as  the  sponge  of 
commerce,  becomes  visible.  In  the  living  animal  the  surface  pre- 
sents a  large  number  of  minute  orifices  or  "  pores/'  and  a  few  much 
larger  ones,  known  as  "  oscules,"  or  excurrent  apertures.    Both  of 
f  Of  the  last-named,  the  pretty  "  Venus  flower-basket  "  {Euplectella  Aspergil- 
lam)  and  the  glass  rope  sponge  (Hyalonema  mirabUe)  are  instances. 
