Whatever the causes may have been, we can see that certain districts and times would have been much more favourable than others for the development of so large a quadruped as the giraffe.

In order that 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 follow that the necessary parts should always vary in the right direction and to the right degree.