86 THE ROYAL SOCIETY OF CANADA 



arrangement was made in 1918 and there is now (December, 1919), 

 a large demand for recleaned screenings on the part of Eastern Canada 

 live stock men. 



Occasional carlots of these recleaned screenings have been un- 

 satisfactory but investigation has usually shown that this is due to the 

 fact that the screenings have not been thoroughly recleaned. 



In addition to the evidence of the feeding experiments reported 

 above, there is a considerable mass of data supporting the belief that 

 it is the presence of the smaller seeds chiefly mustards in elevator 

 screenings that render this material unpalatable to stock and that by 

 cleaning thoroughly enough to remove all seeds as large as hare's-ear 

 mustard, wild mustard, and stinkweed, the average run of screenings 

 makes a valuable food material. 



Deleterious Effects of Certain Weed Seeds 



Sif ton lists six varieties of weed seeds commonly found in elevator 

 screenings which are authoritatively stated to be poisonous and five 

 more that are otherwise objectionable. The poisonous seeds include 

 Brassica arvensis, Brassica nigra. Erysimum cheiranthoides, Thlaspi 

 arvense. Sisymbrium altissimum, Camelina sativa. The ob- 

 jectionable ones are Agrostemma Githago, Lolium temulentum, 

 Saponaria Vaccaria, Lappula echinata, and ergotized grains. 



The various branches of the Federal Department of Agriculture 

 receive an ever-increasing number of feed samples of various kinds that 

 the senders claim have caused the death or serious injury to the health 

 of animals. Analysis of such samples usually reveals the presence of 

 weed seeds of various kinds. As a result of such examinations and the 

 experimentalwork already referred to, it is believed that the difficulty 

 in most cases could have been avoided had the weed seeds entering 

 into the manufacture of such feeds been thoroughly cleaned so as to 

 remove all seeds as large as hare's-ear mustard, wild mustard and 

 stinkweed. 



Considerable harm appears to have resulted during the past few 

 years from the adulteration of mill feeds, including bran and shorts 

 with screenings. 



Poisonous Properties of Flaxseed Screenings 



Difficulties have been encountered in feeding flaxseed screenings 

 unmixed with other grain products. A letter received from a Saskat- 

 chewan farmer under date May 14, 1915, is quoted in part: 



