show the origin of all the species from a common form in one single
class, we have the solution of the problem of man's origin, because we
are in a position to prove clearly his descent from the lower animals.

At the same time, we can now reply to the often-repeated assertion,
even heard from scientists of our own day, that the descent of man
from the lower animals, and proximately from the apes, still needs to
be "proved with certainty." These "certain proofs" have been available
for a long time; one has only to open one's eyes to see them. It is a
mistake to seek them in the discovery of intermediate forms between
man and the ape, or the conversion of an ape into a human being by
skilful education. The proofs lie in the great mass of empirical
material we have already collected. They are furnished in the
strongest form by the data of comparative anatomy and embryology,
completed by paleontology. It is not a question now of detecting new
proofs of the evolution of man, but of examining and understanding the
proofs we already have.

I was almost alone thirty-six years ago when I made the first attempt,
in my General Morphology, to put organic science on a mechanical
foundation through Darwin's theory of descent. The association of
ontogeny and phylogeny and the proof of the intimate causal connection
between these two sections of the science of evolution, which I
expounded in my work, met with the most spirited opposition on nearly
all sides. The next ten years were a terrible "struggle for life" for
the new theory. But for the last twenty-five years the tables have
been turned. The phylogenetic method has met with so general a
reception, and found so prolific a use in every branch of biology,
that it seems superfluous to treat any further here of its validity
and results. The proof of it lies in the whole morphological