INTEODUCTION INTO THE UNITED STATES. 179 



camel thrives have a proper dry season, little or 

 no rain falling during the summer months. But 

 to this rule there are exceptions. The valley of 

 the lower Danube has summer rains, and a very 

 wet autumn, winter, and spring; and many 

 northern Asiatic districts are subject to similar 

 climatic conditions. But the objection, what- 

 ever may be its force, seems to apply merely to 

 the proportion of the year during which the 

 animal can labor, and not to its influence upon 

 his constitution ; because, it appears that in the 

 cold and damp Russian provinces, the camel is 

 less subject to disease, and attains a greater 

 longevity, than in any other part of the world ; 

 and it is remarkable that in the Crimea, he is 

 little used in the hottest and driest season, be- 

 cause the heat is found too great for that variety, 

 and his services are most valuable in winter. 



But there are important exceptions to the 

 general moist character of the North American 

 climate, and these occur precisely in the latitudes 

 where the soil and natural productions are best 

 suited to the habits and wants of the camel, and 

 where at the same time his peculiar properties 

 could be best made available for the service of 

 man. 



The driest and most barren portions of our 

 territory are, 



I. The Great Plain which forms the eastern 



