708 TRANSACTIONS OF SUB-SECTION K. 
of the United States Department of Agriculture upon forests contiguous with 
those of adjacent territories of Canada. 
Fuller knowledge of the life history of the most injurious species is 
required before specific remedial measures can be devised. Among those of 
general application are the prompt removal of mature timber and the 
destruction of harbouring refuse. 
4. Some of the most Injurious Insects of Field Crops in Canada. 
By Professor WiuL1am LocHHEaD. 
Competent observers estimate the loss from depredations by insects to - 
field crops in Canada at not less than fifty millions of dollars annually. 
While the loss cannot be wholly prevented, it could be greatly reduced by 
the general adoption of the measures advocated. In Eastern Canada 
the Hessian fly is doubly brooded, the fall brood appearing in September 
and attacking the young plants of fall wheat, the spring brood appearing 
in May and June and injuring fall wheat as well as spring crops of wheat 
and barley. In Manitoba it is apparently single brooded, the puparia 
remaining dormant on the stubble until spring. The method of control 
recommended for the West is to burn over the stubble of the wheat fields 
or to plough the stubble land down deeply as soon after the crop is cut as 
may be practicable. 
Wireworms and white grubs were dealt with. The remedial measures 
considered were chiefly the systematic rotation of crops. 
5. Chemical Characteristics of Western Prairie Soil. 
By Frank T. Suurt, M.A., F.R.S.C. 
The Canadian prairies comprise all that portion of the Great Plains 
Region north of the forty-ninth parallel and found within the confines of 
the three western provinces, Manitoba, Saskatchewan, and Alberta, and 
extending northward of these provinces to the Arctic Ocean. It consists of a 
stretch of country of some 800 miles from east to west, if measured along the 
southern boundary of these provinces, but contracting to between 300 and 400 
miles at the fifty-sixth parallel. Settlement began in the south of this 
country, and for some years past has been rapidly extending northward. 
This interior plain is made up of three steppes. The first and lowest (with 
an elevation of 800 feet above the sea) is known as the Red River Valley ; its 
northern part being occupied by the Winnipeg lakes, while its southern 
- portion constitutes an apparently absolutely dead-level prairie of almost 
7,000 square miles. It is the bed of the ancient glacial Lake Agassiz, the 
sediment of which is found to make the finest soil for wheat. 
The second steppe, west of the above and extending to the Missouri cotean, 
has an average altitude of 1,200 feet and comprises some 105,000 square miles, 
the soil being undulating in parts and less uniform in character than that of 
the first plateau. 
The third and largest steppe, extending westward of the above to the foot 
hills of the Rocky Mountains, comprises the western part of Saskatche- 
wan and the province of Alberta. Its average altitude is about 3,200 feet 
and its area 134,000 square miles. The northern part is wooded, while an 
open prairie occupies the greater portion in the south. Its topography is 
more diversified than that of the first and second plateaux. 
The meteorological features of this prairie country are high day tem- 
peratures and an abundance of sunshine in the summer months, and an 
annual precipitation of, say, 18 inches in the eastern portion, declining to, 
say, 14 inches in the western. An important fact from the agricultural 
standpoint is that from 70 to 75 per cent. of this rainfall occurs during the 
months of early growth and is therefore particularly effective for cereal 
crops. 
