222 THE DOCTRINE OF DESCENT. 



X. 



The Geographical Distribution of Animals in the light of the Doctrine 

 of Derivation. 



Although ever since the century of the great geo- 

 graphical discoveries, material has been accumulating 

 for a geography of plants and animals, the foundations 

 of scientific botanical geography (apart from George 

 Forster's observations) were first contained in Hum- 

 boldt's celebrated " Ideas on the Physiognomy of Plants " 

 (Ideen zu einer Physiognomik der Gewachse). It is the 

 first description of vegetal forms, comprising the entire 

 area of the earth, and the manner in which, singly or 

 combined, they lend a characteristic impress to the land- 

 scape of their region of distribution, and again on their 

 side harmonize with the other factors of the scene. The 

 celebrated founder of Climatology, who circled the ter- 

 restrial globe with lines of equal temperature, of equal 

 inclination and declination of the magnetic needle, and 

 divided it into dry and rainy zones, knew better than 

 any of his contemporaries that the animal and vegetal 

 world depended on all these factors. Yet neither he 

 nor his followers, before Darwin, rose higher than the 

 description of Nature, which had already checked Buffon 

 in his grand picture of Nature, " Les Epoques de la 

 Nature." 



A natural result of the extraordinary extension of 



