A STUDY OF WHEAT. 



almost impossible to separate the outer and middle coats, 

 that is, a and b of figure 7. If the little specimen we have 

 on the glass slide be turned over we shall see the surface of 

 the middle coat, as seen in figure 9. This coat is composed 

 of a single row of thin-walled cells, each containing its sen- 

 tinel crystal. 



The starch grains of bean are of particular interest, for 

 they contain characteristics peculiar to themselves. The starch 

 grains are oval or round, very similar in shape to the beans them- 

 selves. Then there is a central line or mark through the grain, 

 corresponding to the mark on the back of the bean where it is 



/'V\ r . //. Bean Starc/i after being Boiled, as in Pudding. 



attached to the pod. This line is ragged and uneven in shape, 

 though it marks the nucleus. So great is the resemblance to 

 beans that persons in looking at the starch seem to think they 

 are looking through a glass dimly at the beans themselves. 

 Near the edge of the starch grain, but seldom extending to the 

 center, are seen dark rings, quite fine and numerous. The 

 grains average -g-J-g- of an inch in length, and 10 ' y- of an inch 

 in width. 



When the starch grains of bean are subjected to a high 

 degree of heat, but with no moisture present, the grains be- 



