70 TERRESTRIAL ADAPTATIONS. 



of native products depends,* which appears to be 

 worthy our notice. The difference of the pro- 

 ductions of different countries has a bearing not 

 only upon the physical, but upon the social and 

 moral condition of man. 



The intercourse of nations in the way of dis- 

 covery, colonization, commerce ; the study of the 

 natural history, manners, institutions of foreign 

 countries ; lead to most numerous and important 

 results. Without dwelling upon this subject, it will 

 probably be allowed that such intercourse has a 

 great influence upon the comforts, the prosperity, 

 the arts, the literature, the power, of the nations 

 which thus communicate. Now the variety of the 

 productions of different lands supplies both the 

 stimulus to this intercourse, and the instruments 

 by which it produces its effects. The desire to 

 possess the objects or the knowledge which 

 foreign countries alone can supply, urges the 

 trader, the traveller, the discoverer to compass 

 land and sea ; and the progress of the arts and 

 advantages of civilization consists almost entirely 

 in the cultivation, the use, the improvement of 

 that which has been received from other countries. 



This is the case to a much greater extent than 

 might at first sight be supposed. Where man 

 is active as a cultivator, he scarcely ever bestows 

 much of his care on those vegetables which the 

 land would produce in a state of nature. He 



* It will be observed, that it is not here asserted that the differ- 

 ence of native products depends on the difference of climate alone. 



