proaching the natural conditions as nearly as possible, 
that final and dependable results can be obtained. A 
creditable beginning has been made both in the United 
States and in Canada. Such work along physiological 
lines should be continued as well as research on the pois- 
onous plants from the chemical standpoint. This is the 
immediate need. After proper antidotes and treatment 
have been discovered, however, there still remain two 
problems—one in connection with the utilization of the 
highly complex organic products that some of these 
weeds* contain, products that are very difficult to form 
synthetically in our chemical laboratories; and the other 
concerned with the elimination of the weeds themselves 
from our grain fields, pastures, parks and ranges. The 
importance of such work to the community at large war- 
rants a comprehensive plan of attack and ample govern- 
ment support. 
No bibliography has been compiled. This service has 
been admirably performed in Pammel’s “Manual of Pois- 
onous Plants,” and Long’s “Plants Poisonous to Live- 
stock,” which should be consulted by everyone wishing to 
make a more special study of the subject. References to 
these books and the many publications of the various 
agricultural departments and colleges will be made 
throughout the work. 
The authors wish to express their indebtedness to Pro- 
fessor N. C. Hart, of Western University, and Miss M. V. 
McCulloch, of the Botany Department, University of 
Toronto, for contributions to the illustrations, and to 
Miss Jane McGillicuddy for help in the preparation of the 
*An industrial use has already been found for Wild Mustard, 
Brassica arvensis, the seed of which is being separated from grain 
screenings by special machinery and utilized on a commercial scale, 
at the same time improving the screenings for feeding purposes. 
