Chap. XVII. EVIL FROM INTERBREEDING. 119 



parts of England to be slaughtered; 7 and their merit is now so fully- 

 recognised, that at fat-cattle shows a separate class has been formed for 

 their reception. The best fat ox at the great show at Islington in 1862 

 was a crossed animal. 



The half-wild cattle, which have been kept in British parks probably 

 for 400 or 500 years, or even for a longer period, have been advanced by 

 Culley and others as a case of long-continued interbreeding within the 

 limits of the same herd without any consequent injury. With respect to 

 the cattle at Chillingham, the late Lord Tankerville owned that they were 

 bad breeders. 8 The agent, Mr. Hardy, estimates (in a letter to me, dated 

 May, 1861) that in the herd of about fifty the average number annually 

 slaughtered, killed by fighting, and dying, is about ten, or one in five. 

 As the herd is kept up to nearly the same average number, the annual 

 rate of increase must be likewise about one in five. The bulls, I may add, 

 engage in furious battles, of which battles the present Lord Tankerville 

 has given me a graphic description, so that there will always be 

 rigorous selection of the most vigorous males. I procured in 1855 from 

 Mr. D. Gardner, agent to the Duke of Hamilton, the following account of 

 the wild cattle kept in the Duke's park in Lanarkshire, which is about 

 200 acres in extent. The number of cattle varies from sixty-five to eighty ; 

 and the number annually killed (I presume by all causes) is from eight to 

 ten ; so that the annual rate of increase can hardly be more than one in six. 

 Now in South America, where the herds are half-wild, and therefore offer 

 a nearly fair standard of comparison, according to Azara the natural 

 increase of the cattle on an estancia is from one-third to one-fourth of the 

 total number, or one in between three and four ; and this, no doubt, applies'* 

 exclusively to adult animals fit for consumption. Hence the half-wild 

 British cattle which have long interbred within the limits of the same 

 herd are relatively far less fertile. Although in an unenclosed country 

 like Paraguay there must be some crossing between the different herds, 

 yet even there the inhabitants believe that the occasional introduc- 

 tion of animals from distant localities is necessary to prevent " degene- 

 ration in size and diminution of fertility" 9 The decrease in size from 

 ancient times in the Chillingham and Hamilton cattle must have been 

 prodigious, for Professor Eiitimeyer has shown that they are almost cer- 

 tainly the descendants of the gigantic Bos primigenius. No doubt this 

 decrease in size may be largely attributed to less favourable conditions of 

 life ; yet animals roaming over large parks, and fed during severe winters, 

 can hardly be considered as placed under very unfavourable conditions. 

 ^ With Sheep there has often been long-continued interbreeding within the 

 limits of the same flock; but whether the nearest relations have been 

 matched so frequently as in the case of Shorthorn cattle, I do not know. 

 The Messrs. Brown during fifty years have never infused fresh blood into 

 their excellent flock of Leicesters. Since 1810 Mr. Barford has acted on 

 the same principle with the Foscote flock. He asserts that half a century 



7 Youatt on Cattle, p. 202. 



8 Report British Assoc, Zoolog. Sect., 1838 



* Azara. 'Quadruples du Paraguay, ' torn. ii. pp. 354, 368. 



