The occurrence of successive forms of life upon our globe is an historical fact, which cannot be disputed; and the relation of these successive forms, as stages of evolution of the same type, is established in various cases.
I have devoted my whole life to the study of Nature, and yet a single sentence may express all that I have done. I have shown that there is a correspondence between the succession of Fishes in geological times and the different stages of their growth in the egg,-this is all. It chanced to be a result that was found to apply to other groups and has led to other conclusions of a like nature.
Some species increase, others diminish, and in a short space the generations of living creatures are changed and, like runners, pass on the torch of life.
Unfortunately, most people never observe the natural cycle of birth and death. They do not realize that for one living thing to survive, another living thing must die.
Even in the obscure vast history of a planet the time it takes to make a forest counts. It takes a while. And not every planet can do it; it is no common effect, that tangling of the sun's first cool light in the shadow and complexity of innumberable wind-stirred branches.
Each of us is the next step in evolution along the lineage created by our two parents. Our higher purpose on earth can be found by recognizing what our parents accomplished and where they left off. By reconciling what they gave us with what they left us to resolve, we can get a clear picture of who we are and what we are meant to do.
There is no life higher than the grasstops
So, naturalists observe, a flea; Hath smaller fleas that on him prey; And these have smaller fleas to bite 'em, And so proceed ad infinitum.
The chain of life runs smoothly from one generation to the next and none of the links stand out except here and there a link one sees by accident.