aOQ THE ORIGIN OF SPECIES 



belonging to this same order have not acquired either an 

 elongated neck or a proboscis, cannot be distinctly an- 

 swered; 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 in- 

 crease 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 pro- 

 boscis. To reach the foliage at a considerable height 

 (without climbing, for which hoofed animals are singu- 

 larly ill-constructed) implies greatly increased bulk of 

 body; and we know that some areas support singularly 

 few large quadrupeds, for instance South America, though 

 it is so luxuriant; while South Africa abounds with them 

 to an unparalleled degree. Why 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 develop- 

 ment of so large a quadruped as the giraffe. 



In order that an animal should acquire some structure 

 specially and largely developed, it is almost indispensa- 

 ble that several other parts should be modified and 

 coadapted. Although every part of the body varies 

 slightly, it does not follow that the necessary parts 

 should always vary in the right direction and to the 

 right degree. With the different species of our domesti- 



