Chap. VIL] THEORY OP NATURAL SELECTION. 279 



Mr. Mivart then asks (and this is his second objec- 

 tion), if natural selection be so potent, and if high 

 browsing be so great an advantage, why has not any 

 other hoofed quadruped acquired a long neck and lofty 

 stature, besides the giraffe, and, in a lesser degree, the 

 camel, guanaco, and macrauchenia? Or, again, why has 

 not any member of the group acquired a long proboscis? 

 With respect to S. Africa, which was formerly in- 

 habited by numerous herds of the giraffe, the answer is 

 not difficult, and can best be given by an illustration. 

 In every meadow in England in which trees grow, we see 

 the lower branches trimmed or planed to an exact level 

 by the browsing of the horses or cattle; and what ad- 

 vantage would it be, for instance, to sheep, if kept there, 

 to acquire slightly longer necks? In every district some 

 one kind of animal will ' almost certainly be able to 

 browse higher than the others; and it is almost equally 

 certain that this one kind alone could have its neck 

 slongated for this purpose, through natural selection and 

 the effects of increased use. In S. Africa the competi- 

 tion for browsing on the higher branches of the acacias 

 and other trees must be between giraffe and giraffe, and 

 not with the other ungulate animals. 



Why, in other quarters of the world, various animals 

 belonging to this same order have not acquired either 

 an elongated neck or a proboscis, cannot be distinctly 

 answered; but it is as unreasonable to expect a distinct 

 answer to such a question, as why some event in the 

 history of mankind did not occur in one country, whilst 

 it did in another. We are ignorant with respect to the 

 conditions which determine the numbers and range of 

 each species; and we cannot even conjecture what 

 changes of structure would be favourable to its increase 

 30 



