374 
Commercial  Varieties  of  Cacao.  {A 
The  following  are  the  commercial  varieties  examined :  Ariba, 
Caracas,  Trinidad,  Bahia,  Surinam,  Maracaybo,  Machalle,  Granada, 
Tabasco  and  Java. 
Starch  is  rather  abundant  in  cacao,  on  the  average  about  20  per 
cent.,  but  unless  the  sections  are  very  thin,  it  is  difficult  to  recognize 
in  the  cells,  owing  to  the  abundance  of  fat  (which,  at  ordinary  tem- 
peratures, is  in  the  crystalline  form),  granular  proteids  and  brown 
coloring  matters.  Treatment  with  ether  to  dissolve  out  the  fat 
renders  the  sections  clear  enough  so  that  the  grains  are  easily  seen. 
A  small  portion  of  a  thin  section  of  one  of  the  cotyledons  of  Ariba 
cacao  is  shown,  magnified  750  diameters,  in  Fig.  2  ;  a  and  g  are 
intercellular  spaces ;  b,  cell-wall ;  c,  starch  grain ;  d,  fat  crystals ; 
e,  cell  nucleus  still  visible  in  some  cells ;  and  /,  granular  protoplasm. 
Some  differences  were  found,  in  the  different  samples,  in  the 
quantity  of  starch  present.  In  the  Machelle  variety,  for  example,  it 
was  less  abundant  than  in  the  rest;  but, as  many  grains  showed  evi- 
dences of  partial  disintegration,  there  is  reason  to  believe  that  this 
difference  might  have  been  due  to  the  destruction  of  a  part  of  the 
grains  by  excessive  fermentation  in  the  example  studied. 
In  some  other  specimens,  as  in  the  Caracas  variety,  there  appeared 
to  be  more  than  the  average  number  of  small-sized  grains,  but  this, 
most  likely,  is  not  a  constant  difference,  being  probably  due  to  the 
fact  that  the  seeds  were  not  quite  mature  when  gathered. 
The  most  conspicuous  difference  is  that  in  some  varieties  the 
Fig.  9. — Starch  from  Trinidad  Cacao.    X  1500. 
