372 THE CANADIAN NATURALIST. [Vol. viii. 



be strengthened by facts such as I have just stated ! As a natu- 

 ralist it is my province to study the reasons for the facts. 

 Whether what I call the working of natural laws be called by 

 others the instrumentality of Providence is quite immaterial. 



To recapitulate, I think we may safely deduce the following 

 four rules as governing the Rocky Mountain locust east of the 

 mountains from which it takes its name : — 



(1.) The northwest origin of the more disastrous fall swarms 

 that overrun the more fertile country south of the 44th parallel 

 and east of the 100th meridian. 



(2.) The return migration toward the northwest of the insects 

 that hatch in the country named. 



(3.) The eastern limit of the insects' spread along the 94th 

 meridian. 



(4.) No two successive hatchings of an extensive and disastrous 

 nature can take place in the same region. 



The possibility of exception to the rules would be in keeping 

 with the character of all rules ; but I am convinced that the 

 exceptions will ever prove most trifling. Now there is a deal of 

 satisfaction to be drawn by our farmers from these rules, which 

 not only limit locust disaster but enable them to anticipate 

 events ; and I need hardly state that the accuracy of my own 

 prognostications, repeatedly made during the past three or four 

 years, was in no small degree due to them. 



We have had the spectacle of the Rocky Mountain locust, in 

 what I call the return migration, flying over some parts of the 

 vast territory from the 29th parallel to the Dominion boundary 

 line, and from the 94th meridian to the mountains, all along from 

 the end of April till the beginning of August, and with so little 

 injury that, with the exception of the case in Montana, just men- 

 tioned,* the question everywhere asked is, Where have the flying 

 'hoppers gone ? What has become of them ? I answer that, as 

 in previous years, and as I have always held would be the case, 

 they were, in the main, so diseased and parasitized that they 

 dropped in scattered numbers and mostly perished on their north- 

 ward and northwestward journey. This is no theory, but known 

 to have been the case in the more thickly-settled parts of Kansas, 

 Nebraska, Iowa, and Minnesota, from which the insects that had 

 dropped have been reported, and in some cases sent to me. But 



* Referred to in the portions omitted. — Ed. 



