THEORY OF THE EARTH. 123 



far in half-domesticated species. In the cat, for 

 example, a softer or harsher fur, more brilliant or 

 more varied colours, greater or less size these 

 form the whole extent of the varieties in the spe- 

 cies ; the skeleton of the cat of Angora differs in 

 no regular and constant circumstances from the 

 wild cat of Europe. 



In the domesticated herbivorous quadrupeds, 

 which man transports into all kinds of climates, 

 and subjects to various kinds of management, 

 both in regard to labour and nourishment, he pro- 

 cures certainly more considerable variations, but 

 still they are all merely superficial. Greater or 

 less size; longer or shorter horns, or even the 

 want of these entirely ; a hump of fat, larger or 

 smaller on the shoulder; these form the chief dif- 

 ferences among particular races of the bos taurus, 

 or domestic black cattle ; and these differences 

 continue long in such breeds as have been 

 transported to great distances from the countries 

 in which they were originally produced, when 

 proper care is taken to prevent crossing. 



The innumerable varieties in the breeds of the 

 ovis aries, or common sheep, are of a similar na* 

 ture, and chiefly consist in differences of their 

 fleeces, as the wool which they produce, is a very 

 important object of attention. These varieties^ 

 though not quite so perceptible, are yet sufficient- 

 ly marked among horses. In general the forms 



