A STUDY OF WHEAT. 



seen at D. It must be remembered these cells run around the 

 grain, while in the first and second coats the cells run length- 

 wise. At E, are seen the two seed-coats. Here again there 

 is a slight thickening of the outer cell-walls. The masses of 

 coloring matter are located in the outer layer of , and are 

 seen as little dark crystals. At F, is seen the outer layer of 

 albumen, quite large cells, arranged perpendicular to the sur- 

 face. Inside of all come the regular cells of the center, filled 

 with starch. 



The appearance of the starch under the microscope is very 

 characteristic and peculiar. Pure wheat starch can be obtained 

 by cutting through a grain of wheat and scraping with the 

 point of the knife a little from the central part of the grain 



Fig. 4. Cross 



of Wheat. Drawn with Camera Lucida. X 200. 



on a glass slide. By placing a drop of water on the speci- 

 men and examining it then with a microscope we are pre- 

 pared to study its appearance. There are two distinct kinds 

 of starch grains floating in the field; small, spherical or an- 

 gular starch grains collecting frequently in masses, many times 

 more numerous than the large grains, about 1-200 of a milli- 

 meter, (1-5000 of an inch) in diameter. The others are large 

 lenticular grains, which when viewed on the face, appear like 

 a spherical body, but when viewed on the edge, appear like a 

 double-convex lens, see Fig. 5. This lens shape can easily be 

 proved by touching the cover-glass gently while under the mi- 

 croscope, with a pencil point, and watching the grains roll over 

 in the field, .presenting alternately the appearance of a sphere 

 and a lens. This simple test should always be used when 



