Am.  Jour.  Pharm. 
Aug.,  1890. 
Germination  of  Gr  amine  ce. 
417 
RESEARCHES  ON  THE  GERMINATION  OF  SOME  OF 
THE  GRAMINE^.1 
By  Horace  T.  Brown  and  G.  Harris  Morris. 
The  investigation  was  undertaken  with  a  view  of  throwing  some 
light  upon  the  complex  metabolic  processes  which  take  place  during 
the  germination  of  seeds.  The  authors  during  the  progress  of  the 
inquiry  have  examined  the  seeds  of  a  great  number  of  grasses,  but 
this,  the  first  part  of  their  paper,  is  confined  almost  entirely  to  a 
consideration  of  the  changes  which  take  place  in  barley,  during  the 
early  periods  of  its  growth. 
In  recording  the  visible  changes  which  occur  in  the  seed  during 
germination,  it  is  shown  that  a  disintegration  and  dissolution  of  the 
cell-walls  of  the  endosperm  always  precede  any  attack  upon  the 
cell  contents.  This  breaking  down  of  the  cell-wall  is  shown  in  a 
subsequent  portion  of  the  paper  to  depend  on  the  production  during 
germination  of  a  special  cellulose-dissolving  or  «'  cyto-hydrolytic 
enzyme,"  which,  like  diastase,  is  soluble.  The  action  of  this  enzyme 
on  the  cell- walls  of  some  kind  of  vegetable  parenchyma  is  very 
energetic.  The  physiological  importance  of  this  cyto-hydrolyst  is 
very  great,  for,  owing  to  the  non-diffusible  nature  of  the  amylo- 
hydrolytic  enzyme,  diastase,  the  previous  breaking  down  of  the 
cell-wall  is  a  necessary  prelude  to  the  dissolution  of  the  contained 
starch-granules. 
The  authors  show  that  the  appearance  of  the  cyto-  and  amylo- 
hydrolysts  is  due  to  a  specialized  secretory  function  of  the  layer  of 
columnar  epithelium  which  covers  the  outer  surface  of  the  scutellum. 
It  has  hitherto  been  considered  that  the  functions  of  this  epithelium 
was  exclusively  that  of  an  absorptive  tissue;  its  absorptive  as  com- 
pared with  its  secretory  functions  are,  however,  of  quite  secondary 
importance. 
The  natural  food  material,  starch,  does  not  appear  to  have  any 
special  power  of  stimulating  the  cells  of  the  epithelium  to  increased 
secretion  of  a  diastase,  but  the  flow  of  diastase  and  of  the  cyto- 
hydrolytic  enzyme  from  these  cells  is  affected  in  a  very  remarkable 
manner  by  the  presence  of  certain  carbohydrates.    Providing  the 
1  Read  before  the  Chemical  Society,  London,  April  3  ;  abstract  prepared  from 
Chemical  News,  April  25,  1890,  by  G.  M.  Beringer.  The  paper  printed  in  full 
in  Journal  of  the  Chemical  Society,  June,  occupies  seventy  pages. 
