Chap. I. UNDER DOMESTICATION. 17 



hound, bloodhound, terrier, spaniel, and bull-dog, which 

 we all know propagate their kind so truly, were the off- 

 spring of any single species, then such facts would have 

 great weight in making us doubt about the immutability 

 of the many very closely allied and natural species — for 

 instance, of the many foxes — inhabiting different quarters 

 of the world. I do not believe, as we shall presently 

 see, that all our dogs have descended from any one 

 wild species ; but, in the case of some other domestic 

 races, there is presumptive, or even strong, evidence in 

 favour of this view. 



It has often been assumed that man has chosen for 

 domestication animals and plants having an extra- 

 ordinary inherent tendency to vary, and likewise to 

 withstand diverse climates. I do not dispute that these 

 capacities have added largely to the value of most of 

 our domesticated productions ; but how could a savage 

 possibly know, when he first tamed an animal, whether 

 it would vary in succeeding generations, and whether it 

 would endure other climates ? Has the little variability 

 of the ass or guinea-fowl, or the small power of endurance 

 of warmth by the rein-deer, or of cold by the common 

 camel, prevented their domestication ? I cannot doubt 

 that if other animals and plants, equal in number to 

 our domesticated productions, and belonging to equally 

 diverse classes and countries, were taken from a state 

 of nature, and could be made to breed for an equal 

 number of generations under domestication, they would 

 vary on an average as largely as the parent species of 

 our existing domesticated productions have varied. 



In the case of most of our anciently domesticated 

 animals and plants, I do not think it is possible to come 

 to any definite conclusion, whether they have descended 

 from one or several species. The argument mainly 

 relied on by those who believe in the multiple origin 



