To the mass of mankind religion of some kind is a necessity.

But naturalists are now beginning to look beyond this, and to see that there must be some other principle regulating the infinitely varied forms of animal life.

What we need are not prohibitory marriage laws, but a reformed society, an educated public opinion which will teach individual duty in these matters.

If this is not done, future ages will certainly look back upon us as a people so immersed in the pursuit of wealth as to be blind to higher considerations.

Modification of form is admitted to be a matter of time.

In all works on Natural History, we constantly find details of the marvellous adaptation of animals to their food, their habits, and the localities in which they are found.