THE VOLATILE PART OF PLANTS. 



Ill 



albuminoid, or mixture of albuminoids, but the organ- 

 ized granules found iu the plant, of which the albumin- 

 oids are chief or characteristic 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, c, are chiefly occupied with very 

 fine grains of aleurone. In one cell, t, are seen tlie 

 much larger starch grains. In the interior of the oat 

 kernel, and other cereal seeds, the cells are chiefly occu- 

 pied 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, a, contain vegetable muci- 

 lage ; 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 

 grains ; a is aleurone 

 from the seed of the vetch, i from the castor-bean, c 

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

 cerifera) and e from mace (an appendage to the nutmeg, 

 or fruit of the Myristica moscfiata). 



Crystalloid aleurone. — It has been already remarked 



e 



Fig. 20. 



Fig. 21. 



that crystallized albuminoids exist in plants. This was 

 first observed by Hartig {Entwichelungsgeschichte des 



