100 STATISTICS OF MINNESOTA. 



The whole of Poland, except in the south, is an extended plain, 

 and Russia, west of the Ural mountains, is pretty much all an 

 immense plain, the southern part being the finest part of Russia, 

 and a locust country par excellence. All that part of it extending 

 eastward from the Black Sea, lying above the sea of Azof and the 

 Caspian, on to the Ural mountains, is little better than a desert, 

 being level, dry and barren, and abounding in salt lakes. But 

 after all, what is there certain about this? What is the exact 

 agency of deserts or of mountains? High mountains produce 

 deserts by straining the moisture from the atmosphere. They exist 

 side by side in some localities as a matter of necessity. The des- 

 erts must be passed over if the locust is to live at all. It is quite 

 possible that he is only more destructive in the populous and fer- 

 tile valley regions because a greater population are affected, and 

 there is more there to be destroyed. When the locust once acquires 

 wings, he moves; he does not seem to exercise much judgment 

 whether it be from plenty to want or the reverse. He will move 

 from a desert country, as east of the Rocky Mountains, to a fertile 

 one, and he tries to move or is moved by the wind right back again 

 into the same desert, the next year more often than otherwise, this 

 being his cycle of migration — unfortunately, for the last four years 

 unswung. 



After having traversed the ground thus far, the question arises: 

 what inferences are to be drawn from the facts obtained I 



The subject is difficult to cope with, from the absence of any- 

 thing like scientific accuracy in the observation of facts as given 

 # in the earlier records. Nevertheless, a few general ideas are sug- 

 gested in the midst of this chaos, which assume a certain degree of 

 prominence and fixity, among which are — 



First. That there are certain portions of the globe where the 

 locust exists en permanence ; where he has flourished from age to 

 age in unending succession, and that the type of such a region in 

 the eastern hemisphere is found in Arabia and northern Africa. 



Secowt. That there are other portions where, practically speak- 

 ing, it does not exist at all, the type of which is found in the north 

 of Europe and the British islands. 



Third. That thei'O are regions intermediate between these 

 which are liable to be overrun by occasional migrations from the 

 natural parent hives. And the type of these countries in the same 

 hemisphere is the whole of Southern Europe from Gibralter in 

 Spain, to the Ural Mountains in Russia. The analogy of any 

 given country in geographical and climatological conditions to any 



