43 



Under the hand lens it is easily seen that the transverse wrin- 

 kles on the glume of glaiica are much more prominent than those 

 on viridis owing to their being further apart. 



Figure 39 

 Fig. 39. Green and Yellow Foxtail. 



The glumes are the chief means of identification, and closely 

 envelop the grain when ripe. The cells in surface view are thick 

 walled, with very sinuous side walls and the end walls also are 

 usually sinuous. They are arranged in longitudinal rows and to 

 some extent in transverse rows as well. 



The folds of the cell walls are very regular. In size and shape 

 the cells vary somewhat, depending whether they are taken 

 from the middle or edge of the glume, but are usually from once 

 and a half to twice as long as broad. 



Usually, however, the seeds occur whole, and a glance at them 

 under a hand lens is sufficient for their identification. (Fig. 39.) 



ALFALFA. 



Occasionally the seeds of alfalfa are found as an impurity in 

 some cattle feeds, principally those containing wheat, but lately 

 chopped alfalfa hay is used in some feeds. It is usually chopped 

 fine and may be recognized by its green color and odor. Usually 

 it is not necessary to make a microscopic examination of the 

 specimen, as the characteristic odor and color are the best indi- 

 cations of its presence. 



COCOA SHELLS. 



These are used in a number of ways in commerce, and are 

 often found in cattle feeds as well as in human foods. 



