106 



HOW CROPS GROW. 



meant simply an albuminoid, or mixture of albuminoids, 

 but the organized granules found in the plant, of which 

 the albuminoids are chief ingredients. 



In Fig. 18 is represented a magnified slice through the 

 outer cells, (bran,) of a husked oat kernel. The cavities 

 of these outer cells, a, o, are chiefly occupied with very 



Fig. 18. 



Tig. 19. 



fine grains of aleuronc, (casein.) In one cell, Z>, arc seen 

 the much larger starch grains. In the interior of the oat 

 kernel and other cereal seeds, the cells are chiefly occupied 

 with starch, but throughout grains of aleurone are more 

 or less intermingled. 



Fig. 19 exhibits a section of the exterior part of a flax- 

 seed. The outer cells, , contain vegetable mucilage ; the 

 interior cells, e, are mostly filled with minute grains of 

 aleurone, among which droplets of oil,/", are distributed. 



In Fig. 20 are 

 shown some of the 

 forms assumed by in- 

 dividual albuminoid- a b c d e 

 grains ; a is aleurone Fig. 20. 

 from the seed of the vetch, b from the castor bean, c 

 from flax-seed, d from the fruit of the bnyberry, (Myrica 



