386 
On  Cotton  Seeds, 
f  Am.  Jour.  Phaem. 
t    Sept.  1, 1871. 
parts  of  America,  particularly  Central  America  and  the  West  Indies  ; 
the  former  is  now  most  extensively  cultivated  in  consequence  of  the 
excellence  of  its  cotton.  In  the  Southern  States  of  North  America 
it  yields  the  valued  Georgia,  or  Sea  Island  cotton  ;  it  is  also  cultivated 
in  Western  Africa,  Egypt,  East  Indies  and  Australia.  Cr.  hirsutum 
is  distributed  to  the  same  extent,  and  grows  well  in  Southern  Italy  ; 
the  upland  cotton,  short  staple,  Siam,  Castellamare,  and  Malta 
cotton  comes  from  this  species.  G.  religiosum^  probably  indigenous 
to  Peru,  requires  a  warmer  climate,  but  is  cultivated  in  some  localities 
south  of  the  Mediterranean.  Cr.  herhaceum^  owing  to  the  small  cap- 
sule, gives  a  smaller  yield ;  its  purely  white  fibre,  however,  is  better 
than  that  of  (r.  arho7'eum\  which  yields  the  lowest  grade  of  cotton. 
The  species  from  Polynesia  and  Central  Africa  appear  not  to  be  cul- 
tivated yet. 
Like  all  the  extensively  cultivated  plants  which  are  spread  over  a 
considerable  area,  we  find  in  this  genus  numerous  varieties  which  are 
distinguished  with  difficulty  in  consequence  of  the  confusion  existing 
in  their  nomenclature.  Parlatore  found,  even  in  botanical  gardens, 
varieties  of  Cr.  religiosum  under  the  name  of  Gr.  arhoreum. 
The  cotton  fibres,  which  originate  from  the  cells  of  the  epidermis 
of  the  testa,  are  readily  removed  from  the  seeds  of  G.  harhadense  ; 
they  adhere  more  firmly  in  G.  anomalum,  hirsutum,  sandvieense  and 
taiteiise.  G.  religiosum  has  the  spinning  fibres  not  firm,  but  besides 
them,  the  testa  has  a  brown  reddish  covering  of  short  hairs.  G.  ar- 
horeum and  herhaceum  have  seeds  to  which  not  only  the  cotton,  but 
also  the  greenish  or  greyish  felt-like  covering  firmly  adhere. 
The  removal  of  the  spinning  fibres,  by  peculiar  machines,  without 
touching  the  felt  cover,  is  accomplished  with  almost  perfectness  from 
G.  harhadense,  while,  owing  to  the  described  structure,  the  cotton  is 
rather  torn  off  from  the  seeds  of  the  other  species.  The  excellence  of 
the  sea  island  cotton  and  some  other  varieties  partly  depends  upon 
this  dilference. 
The  anatomical  structure  of  the  seeds  is  then  minutely  described 
and  illustrated  by  microscopical  drawings  of  sections  of  the  testa  and 
of  a  cotyledon. 
The  complicate  contents  of  the  large  tannin  cells  in  the  cotyledons, 
containing  also  granules  of  a  beautiful  violet  coloring  matter,  are 
dissolved  by  the  oil,  if  this  is  expressed,  and  impart  to  the  latter  an 
unsightly  brown  color,  even  if  the  testa  had  been  previously  removed. 
