VARIATION UNDER DOMESTICATION 13 



the whole amount of difference between the several breeds of the 

 dog has been produced under domestication; I believe that a small 

 part of the difference is due to their being descended from distinct 

 species. In the case of strongly marked races of some other domes- 

 ticated species, there is presumptive or even strong evidence that 

 all are descended from a single wild stock. 



It has often been assumed that man has chosen for domestica- 

 tion animals and plants having an extraordinary inherent tendency 

 to vary, and likewise to withstand diverse climates. I do not dis- 

 pute 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 cli- 

 mates? Has the little variability of the ass and goose, or the small 

 power of endurance of warmth by the reindeer, or of cold by the 

 common camel, prevented their domestication? I cannot doubt 

 that if other animals and plants, equal in number to our domesti- 

 cated 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 on an average vary 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, it is not possible to come to any definite conclusion, 

 whether they are descended from one or several wild species. The 

 argument mainly relied on by those who believe in the multiple 

 origin of our domestic animals is, that we find in the most ancient 

 times, on the monuments of Egypt, and in the lake-habitations of 

 Switzerland, much diversity in the breeds; and that some of these 

 ancient breeds closely resemble, or are even identical with, those 

 still existing. But this only throws far backward the history of 

 civilization, and shows that animals were domesticated at a 

 much earlier period than has hitherto been supposed. The lake- 

 inhabitants of Switzerland cultivated several kinds of wheat and 

 barley, the pea, the poppy for oil, and flax; and they possessed, 

 several domesticated animals. They also carried on commerce^) aiJaw 

 with other nations. All this clearly shows, as Heer has remarked, / . 

 that they had at this early age progressed considerably in civiliza- I Z 

 tion; and this again implies a long continued previous period of / 

 less advanced civilization, during which the domesticated animals, 1 

 kept by different tribes in different districts, might have varied y 

 and given rise to distinct races. Since the discovery of flint tools 

 in the superficial formations of many parts of the world, all 



