A STUDY OF WHEAT. 



55 



cells. The walls of the ou^er layer are wavy, but not beaded 

 as in wheat. There are three layers of transverse cells and 

 the walls are not wavy. There are also generally three layers 

 of cells containing the gluten or nitrogenous substances. All 

 of these cells are more delicate than the 'corresponding ones 

 of wheat. The cells of the central part containing starch are 

 also more delicate, and when empty resemble thin walled fibrous 

 structure. 



If we cut open a kernel of barley and scrape a little of the 

 white powder from the center, we will find there are present 

 two kinds of starch grains, both large and small. The large 

 grains are lenticular ; when seen on the face they arc round 

 or nearly so, but when seen on the edge they are oval, fre- 

 quently showing a longitudinal furrow. A faint nucleus is present 



Fig. i. Barley Starch. X 475. (Drawn with the camera 



and faint rings are seen in a few of the grains, though not in 

 all of them. The average size is about one sixteen-hundredth 

 of an inch in diameter. The small grains are angular, dark 

 .and not collected in masses as in many of the starches. The 

 whole appearance of barley starch is much more delicate than 

 that of wheat. The large grains are smaller, more nearly spher- 

 .ical and more opaque. The small grains are smaller, more uni- 

 form in size and fewer in number than the corresponding ones 



