A STUDY OF WHEAT. 



FRUIT-COATS f 

 OR -I 



1 . Outer fruit-coat, or epidermis, or EXOCARP. 



2. Middle fruit-coat, or MESOCARP. 



3. Inner fruit-coat, or ENDOCARP. 

 PERICARP. |_ 4. Vascular bundle. 



SEED- COATS. 



ALBUMEN. 



EMBRYO. 



j 5. Outer seed-coat, or TESTA. 



( 6. Inner seed-coat, or ENDOPLEURA. 



{7. A single layer of large cells filled with gluten and nitro- 

 genous products PERISPERM. 

 8. Large hexagonal cells filling the central part of the grain and 

 loaded with starch, etc. ENDOSPERM. 



( 9. A single layer of empty compressed cells. 



-] 10. Regular hexagonal cells of the embryo filled with starch,. 



( oil, etc. 



As we understand the term "bran," it includes the first seven 

 of these parts, that is, all of the different coats of the wheat. 



i. The outer fruit-coat, or the epidermis, consists of a single 

 layer of cells see, Fig. i. similar in appearance to those found in 

 the epidermis of the straw, long, narrow cells with a strong cell- 

 wall, looking something like a string of beads. An important thing 

 to remember is that the longest way of the cells is with the length 

 of the grain. About the center, that is, midway between the two 

 ends on the surface, these cells are in length nearly three times the 

 width, while as they approach either end they gradually grow 

 shorter and rounder. Occasionally stomates are found in the epi- 

 dermis, but not regularly as in the straw. At the apex of the grain, 



Fig. i. Epidermis or First Frttit-coat of Wheat. X 75. 



and growing out from this layer of cells, are the long slender hairs 

 seen in Fig. 2; "A" shows the epidermis and the way the hairs are 

 embedded in the cells. These hairs are composed of a single cell 



