On The Origin of Species by Charles Darwin Chapter 14 Page 63

plan of creation, we may hope to make sure but slow progress.

Professor Haeckel in his “Generelle Morphologie” and in another works, has recently brought his great knowledge and abilities to bear on what he calls phylogeny, or the lines of descent of all organic beings. In drawing up the several series he trusts chiefly to embryological characters, but receives aid from homologous and rudimentary organs, as well as from the successive periods at which the various forms of life are believed to have first appeared in our geological formations. He has thus boldly made a great beginning, and shows us how classification will in the future be treated.

4. Morphology

We have seen that the members of the same class, independently of their habits of