84 COMMERCIAL FEEDING STUFFS. 



SORREL. 



Rumex acetosella L. 



These seeds in general shape are like those of R. crispus L. (p. 83) 

 but are 1.25 to 1.50 mm in length, of a dull brown color, and have a 

 somewhat roughened surface. 



The sorrel seed coats are readily split into two ovate-shaped halves. 

 Cleared and examined "under the microscope, the surface will be found 

 to be covered with strongly convoluted ridges, which are more or less 

 parallel from end to end. (Plate III, fig. 1.) 



FOXTAIL. 



CJiaetochloa sp. 



The seeds of C. glauca (L.) Scribn. are about 3 mm by 2 mm, strongly 

 flattened on the palet side, and of a dull greenish yellow color. The 

 seeds of green foxtail C. viridis (L.) Scribn. are the shape of C. glauca 

 but with a more convex palet and about one-half to two-thirds the 

 dimensions. In color they vary from pale green to brown. 



The principal structures for identification of the foxtails are the 

 glumes and palets, and in a ground condition it seems rather difficult 

 to differentiate CJiaetochloa glauca from CJiaetochloa viridis. The 

 ridges on C. glauca usually can be seen in material which has been 

 partially cleared in chloral hydrate, while in C. viridis (Plate III, 

 fig. 2) most of the epidermal cells form projections which in the case of 

 the palet are especially characteristic, and a careful examination of 

 these two features will usually enable the worker to identify the two 

 species. 



