144 



Agricultural Section 



[PT II 



arvensis and S. oleraceus, Prunella vulgaris, Chrysanthemum leu- 

 canthemuni, Aira caryophyllea, etc. (see Figs. 43, 99, 114, 158 

 to 164, and 170). Most of these can be removed by modern 

 machinery and samples containing more than one per cent, should 

 be rejected. 



Fig. 158 Fig. 159 Fig. 160 



Common impurities in Crested Dog's-tail Seed. 

 Fig. 158. Chrysanthemum leucaiithemuni, L. Ox-eye Daisy. 

 Fig. 159. C'repis virens, L. Smooth Crepis. 

 Fig. 160. Poa allium, L. Each x 10. 



Small seeds of Rye-grass and Cock's-foot, and seeds of Timothy, 

 and Hard Fescue commonly occur as impurities. 



Fig. 161. "Seeds" of the Common Sowthistle {Sonchus oleraceus, L.). x6. 



The chaff should not exceed one per cent, by weight, and the 

 Purity should easily reach 97 to 99 per cent, The Germination 

 of good seed will reach 50 to 60 per cent, in seven days, and 85 to 

 90 per cent, in 21 days. Sometimes 28 days are required to ascer- 

 tain its full germination capacity. 



