Chap. ILL SHEEP I THEIR VARIATION. 97 



slaughtered ; so that each owner must determine which shall 

 he killed and which preserved for breeding. In every district, 

 as Youatt has remarked, there is a prejudice in favour of the 

 native breed ; so that animals possessing qualities, whatever 

 they may be, which are most valued in each district, will be 

 oftenest preserved ; and this unmethodical selection assuredly 

 will in the long run affect the character of the whole breed. 

 But it may be asked, can this rude kind of selection have been 

 practised by barbarians such as those of southern Africa ? In 

 a future chapter on Selection we shall see that this has 

 certainly occurred to some extent. Therefore, looking to the 

 origin of the many breeds of cattle which formerly inhabited 

 the several districts of Britain, I conclude that, although 

 slight differences in the nature of the climate, food, &c, as 

 well as changed habits of life, aided by correlation of growth, 

 and the occasional appearance from unknown causes of con- 

 siderable deviations of structure, have all probably played 

 their parts ; yet that the occasional preservation in each 

 district of those individual animals which were most valued 

 by each owner has perhaps been even more effective in the 

 production of the several British breeds. As soon as two or 

 more breeds were formed in any district, or when new breeds 

 descended from distinct species were introduced, their crossing, 

 especially if aided by some selection, will have multiplied the 

 number and modified the characters of the older breeds. 



Sheep. 



I shall treat this subject briefly. Most authors look at our 

 domestic sheep as descended from several distinct species. 

 Mr. Bly th, who has carefully attended to the subject, believes 

 that fourteen wild species now exist, but " that not one of 

 them can be identified as the progenitor of any one of the 

 interminable domestic races." M. Gervais thinks that 

 there are six species of Ovis, 73 but that our domestic sheep 

 form a distinct genus, now completely extinct. A German 



73 Blyth, on the genus Ovis, in Mr. Blyth's excellent articles in ' Land 



'Annals' and Mag. of Nat. History,' and Water,' 1867, pp. 134, 158. 



vol. vii., 1841, p. 261. With respect Gervais, 'Hist. Nat. des Mammiieres, 



lo the parentage of the breeds, see 1855, torn. ii. p. 191. 



