82 CATTLE. Chap. III. 



the feral pigs of Jamaica. From these several facts we see 

 that with pigs when feral there is a strong tendency to 

 revert to the wild type ; but that this tendency is largely 

 governed by the nature of the climate, amount of exercise, 

 and other causes of change to which they have been 

 subjected. 



The last point worth notice is that we have unusually good 

 evidence of breeds of pigs now keeping perfectly true, which 

 have been formed by the crossing of several distinct breeds, 

 The Improved Essex pigs, for instance, breed very true ; but 

 there is no doubt that they largely owe their present excellent 

 qualities to crosses originally made by Lord Western with the 

 Neapolitan race, and to subsequent crosses with the Berkshire 

 breed (this also having been improved by Neapolitan crosses), 

 and likewise, probably, with the Sussex breed. 30 In breeds 

 thus formed by complex crosses, the most careful and unre- 

 mitting selection during many generations has been found to be 

 indispensable. Chiefly in consequence of so much crossing, 

 some well-known breeds have undergone rapid changes ; thus, 

 according to Nathusius, 31 the Berkshire breed of 1780 is quite 

 different from that of 1810 ; and, since this latter period, at 

 least two distinct forms have borne the same name. 



Cattle. 



Domestic cattle are certainly the descendants of more than 

 one wild form, in the same manner as has been shown to be the 

 case with our dogs and pigs. Naturalists have generally 

 made two main divisions of cattle : the humped kinds inhabit- 

 ing tropical countries, called in India Zebus, to which the 

 specific name of Bos indicus has been given ; and the common 

 non-humped cattle, generally included under the name of 

 Bos taurus. The humped cattle were domesticated, as may 

 be seen on the Egyptian monuments, at least as early as the 

 twelfth dynasty, that is 2100 B.C. They differ from common 

 cattle in various osteological characters, even in a greater 



30 S. Sidney's edition of Youatt on 31 ' Sohweinesfhadel/ s 140. 



the Tig,' 1860, pp. 7, 26, 27, 29, 30. 



