MAN AS AN AGENT. 



Man is an agent in many different ways of which the follow- 

 ing may serve as illustrations: (a) impure seeds; (b) railways; 

 (c) vehicles; (d) threshing machines ; (e) cultivation; (f) pack- 

 ing materials; (g) wool; (h) plants cultivated for ornamental 

 purposes; (ij cultivated for food. 



Impure Seeds. Many weed seeds are scattered with various 

 agricultural and garden seeds. Buckhorn, dodder, wild carrot, 

 ragweed, nimble will, bracted plantain, dock, quack grass, chic- 

 ory, Canada thistle and many other weeds have been scattered 



Some of the impurities found in alfalfa : la alfalfa seed, Ib toothed 

 bur-clover, Jc spotted bur-clover, 2c yellow trefoil, 2b seed natural size, 

 Sd pod, Sa sweet clover, 36 seed natural size, Jc bracted plantain (Plan- 

 tago aristata), 5 buckhorn (Plantago lanceolata) , 6 sour dock, 7 Canada 

 thistle, 8 dodder, 9 quack grass, 10 sheep sorrel, 11 wire grass or Canada 

 bluegrass (Poa compressa), 12 bluegrass. (Lettered figures after Hillman.) 



with Agricultural seeds. One farmer in Iowa sent to rne twenty 

 different kinds of weeds found in his clover meadow which were 



