212 MiaCELLANEOUS 0BJEGTI0N8 TO THE 



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 advantage would it be, for in- 

 stance, 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 elongated for this purpose, through 

 natural selection and the effects of increased use. In 

 South Africa the competition 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 while 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 favorable to its increase in some new country. 

 We can, however, see in a general manner that various 

 causes might have interfered with the development of a 

 long neck or proboscis. To I'each the foliage at a consid- 

 erable height (without climbing, for which hoofed animals 

 are singularly ill-constructed) implies greatly increased 

 bulk of body; and we know that some areas support singu- 

 larly few large quadrupeds, for instance South America, 

 though it is so luxuriant, while South Africa abounds 

 with them to an unparalleled degree. AVhy this should be 

 so we do not know; nor why the later tertiary periods 

 should have been much more favorable for their existence 

 than the present time. Whatever the causes may have 

 been, we can see that certain districts and times would have 

 been much more favorable than others for the development 

 of so large a quadruped as the giraffe. 



In order tlaat an animal should acquire some structure 

 specially and largely developed, it is almost indispensable 

 that several other parts should be modified and coadapted. 

 Although every part of the body varies slightly, it does not 



