32 EXPERIMP:NT station. [Jan. 



walls will pass through the digestive tract uniDJured and later 

 germinate. 



The principal weed seeds found were as follows : corn-cockle, 

 charlock, Jimson weed, wild turnip, rib grass, broad-leaved 

 plantain, bindweed, lady's thumb, bouncing Bet, ragweed, medi- 

 cago, lamb's-quarters, green and yellow foxtail, curled dock, 

 bitter dock, crab grass, pigweed, darnel, clotbur, bur clover, 

 dodder, and occasionally others. Nearly all of the weeds men- 

 tioned above may be classed as noxious, and are a menace to 

 any farm. Three of them — corn-cockle, darnel and Jimson 

 weed — are harmful to cattle on account of the alkaloidal prin- 

 ciples they contain, and are poisonous to animals when eaten by 

 them in large quantities. 



A detailed description of several of the more commonly oc- 

 curring weed seeds is given below, by use of which it is hoped 

 the reader may identify them when present in a feed or in 

 grass seed. 



Charlock or Wild Mustard (Sinapis arvensis, L.). — 

 Wild mustard is very often found in feeds and occasionally in 

 grass seeds. In appearance it is similar to rape seed, but much 

 smaller. It is a deep brown to dull black in color, and nearly 

 spherical in shape, and under a reading glass or hand lens the 

 surface of the seed appears smooth. In size the seed is about 

 Me of an inch or less in diameter. When growing in the field it 

 is easily recognized by its bright yellow flowers. 



CoR^^-cocKLE, Cockle (Agrosiemma gitJiago, L.). — This 

 seed is very often found in feed stuffs, and when present in any 

 great number is injurious to cattle on account of the poisonous 

 alkaloid, sapotoxin, which it contains. The seed is roughly kid- 

 ney shaped, resembling " a rolled up caterpillar." In size the 

 seed is from Kg to %6 of an inch in diameter, and in color varies 

 from brownish black to dead black. The surface is rough, and 

 to the naked eye there seem to be parallel rows of minute 

 projections over the whole seed. When cut open the seed is 

 found to be filled with a mealy white substance, forming a 

 strong contrast to the black outside covering. 



Jimson Weed, Jamestown Weed (Datura siramonium, L.). 

 — This weed is occasionally found as an impurity in commer- 

 cial products, and is very harmful to animal life on account of 



