MODERN VIEWS ON EVOLUTION 187 



The main result of Darwin's indefatigable labours 

 on the formation of domestic races could not be more 

 accurately summarized than In these words published 

 in 1826. 



Prichard expresses himself as uncertain whether 

 domestic animals are more prone to vary than others, 

 but considers that the artificial conditions may In all 

 probability * occasion deviations in their progeny '. 



The influence of climate seemed to him the most impor- 

 tant of all causes of race-formation — so important in fact 

 that he discusses Its examples under a separate Section, 

 while the adaptation of races, animal and human, to their 

 climates form the subjects of the concluding Sections vi 

 and vii. 



The examples of the effect of climate are brought 

 forward in Section v (p. 558), entitled, Instances of 

 variety in the Breed, arising from the operation 

 of external, chiefly of local causes. The first instance 

 is that of the swine of Cuba, which are said to be twice 

 the size of the parent breed. He then instances the 

 peculiar and uniform colour of the cattle and horses 

 ' descended from the variegated domestic breeds ' which 

 have become wild in South America, and the common 

 bear, which differs In colour in various European localities. 



When the races of several distinct species resemble 

 each other In a single locality It Is fairly maintained that 

 some special local influence may be strongly inferred. 

 Thus it Is stated that the Angora breeds of rabbits, goats, 

 and cats are remarkable for their long, fine, silky hair, and 

 white colour. ' These characters . . . indicate a common 

 cause, which must be some peculiarity in the circumstances 

 under which these animals exist in the climate and 

 situation occupied by them.' 



Then follow many other examples — the blackness which 

 characterizes both men and animals in Malabar and 

 Guinea, the whiteness of Polar animals, the height of 

 Patagonian man, the differences which separate the 

 English race in America and the West Indian Islands 

 from that In the parent country, and the negroes of 

 America from those of Africa. 



