Species of the same genus would occasionally exhibit reversions to lost ancestral characters.

It is no valid objection that science as yet throws no light on the far higher problem of the essence or origin of life. Who can explain the what is the essence of the attraction of gravity?

We cannot fathom the marvelous complexity of an organic being; but on the hypothesis here advanced this complexity is much increased. Each living creature must be looked at as a microcosm--a little universe, formed of a host of self-propagating organisms, inconceivably minute and as numerous as the stars in heaven.

Physiological experiment on animals is justifiable for real investigation; but not for mere damnable and detestable curiosity.

We will now discuss in a little more detail the Struggle for Existence.

It may be doubted whether any character can be named which is distinctive of a race and is constant.