226  The  Structure  of  the  Starch  Grain.  {AmMav'"iS-arrn 
finally  ruptures  {fig.  8)  and  then  follows  a  gradual  solution  of  the 
grain,  the  peripheral  layer  sometimes  recurving  like  the  cutin  layer 
of  an  epidermal  cell  on  treatment  with  sulphuric  acid  {figs,  p,  id). 
Figs.  23-34  — Corn  starch  grains,  showing  the  effect  of  chromic  acid  and 
other  swelling  reagents. 
In  wheat  starch  (figs.  11-22)  the  development  of  the  crystalloidal 
character  of  the  lamellae  (figs,  nt  12)  is  followed  by  the  formation 
of  narrow,  interrupted  or  continuous,  radial  channels  near  the  per- 
iphery of  the  grain  (fig.  13),  which  are  sometimes  connected  with 
