£04 
Aleurone, 
(  Am.  Jour.  Pharm. 
t      Feb.,  1880, 
contain  aleurone  together  with  starch  and  oily  matter.  If  the  seeds 
contain  much  starch,  as  in  the  chestnut,  the  aleurone  grains  occupy  the 
interstices  and  consist  of  minute  granules ;  in  oily  seeds,  however,  the 
granules  are  found  in  the  place  of  starch. 
Their  formation  commences  when  the  seeds  have  attained  their  last 
condition  of  ripeness  and  the  funiculus  become  sapless  ;  the  seed  loses 
water  by  evaporation,  the  mucilaginous  mass  in  its  interior  gradually 
becoming  firmer,  and  the  grains  of  aleurone  separate  from  the  turbid 
■matrix. 
The  origin  of  the  grains  is  therefore  simply  a  dissociation  which 
arises  from  loss  of  water  ;  on  germination,  the  cells  absorb  moisture, 
and  the  aleurone  grain  again  unites  with  the  matrix. 
The  matrix  surrounding  the  grain  may  be  considered  as  the  proto- 
plasmic mass  of  the  cell,  in  which  water  is  replaced,  on  drying,  by  oil 
or  starch. 
The  use  of  aleurone  is  to  act  as  a  reservoir  of  protein,  in  the  same 
way  as  starch  and  oil  globules  are  reservoirs  of  hydrocarbons,  the  pro- 
tein being  the  source  from  which  the  protoplasm  of  the  young  plant  is 
formed  upon  germination. 
Occasionally  the  grains  are  seen  to  have  a  crystalline  appearance, 
due  to  their  enclosing  crystals  of  oxalate  of  calcium  ;  more  frequently, 
however,  they  contain  non- crystalline  and  clustered  granules  of  a  double 
phosphate  of  calcium  and  magnesium  mechaiiicallv  enveloped  during 
the  contraction  of  the  protein. 
Aleurone  grains  are  absolutely  insoluble  in  alcohol,  ether,  benzol  or 
chloroform  ;  they  are  mostly  soluble  in  water,  and  can  by  that  means 
be  separated  from  the  enclosed  crystals  or  globoids. 
Their  chemical  composition  has  recently  been  made  the  subject  of 
observation  by  several  chemists.  In  1872,^  Ritthausen  exhausted  the 
seeds  by  alkaline  ^solutions  and  demonstrated  the  presence  of  vegetable 
caseins,  such  as  legumin  and  conglutin. 
In  1877,^  Weyl  published  some  observations  which  tended  to  show 
that  the  proteids  existed  as  globulins,  and  that  the  caseins  extracted  by 
E-itthausen  were  the  products  of  alteration  caused  by  his  alkaline  solu- 
tions. 
^  "Die  Eiwelss-Korper  cler  Getreidearten,"  1872. 
-  "  Zeitschr.  fiir  Physiol.  Chemie,"  1877. 
