THE EFFECTS OF DOMESTICATION. 5 



to imagine that all our breeds of sheep may have been 

 descended from one wild form. That this has actually been 

 the case cannot be asserted, and in fact is scarcely likely to 

 be true. Wild species of all animals vary with the con- 

 ditions of climate and food under which they live. The 

 original native sheep of England, if such there was, would 

 probably be slightly different from the wild sheep of the 

 Continent of Europe or of Asia, or even from the original 

 sheep of northern and of southern Europe. 



Whether our sheep were originally brought from Asia in 

 the train of conquering armies, as was no doubt the case with 

 the ancestors of many of our domesticated animals, may be 

 considered an open question, excepting that we can hardly 

 imagine that they were absent from those vast migrations of 

 the human family. They, however, existed in Europe in the 

 Stone period, although in less number than goats. The pro- 

 bability is that domesticated sheep originated through the 

 domestication of several races in many parts of the world, 

 the peculiarities and valuable properties of each having been 

 developed by selection, until a more or less perfect type was 

 obtained. 



It is one of the peculiarities induced by domestication that 

 animals, although descended from different stocks, which in 

 the wild state would not have mated together, breed freely, 

 and produce fertile offspring. Such is the case between the 

 sus scrofa, or European pig, and the specifically distinct sus 

 indica, or Chinese hog. Also between the buffalo and bison, 

 and ordinary cattle. It has also been shown to have been 

 the case between the different species of oxen from which our 

 European cattle are now usually supposed to be descended. 



The crossing of species ot sheep originally distinct has no 

 doubt still further increased the number of our recognised 

 breeds. 



Lastly, there is the continued breeding of animals by men 

 who have had a particular object and type of animal in view. 

 The cattle possessed by the different tribes of Caffres of 



