The Evolution of Man, vol 1 | Page 4

series of illustrations has been considerably
improved and enlarged; there is no scientific work published, at a price
remotely approaching that of the present edition, with so abundant and
excellent a supply of illustrations. When it was issued in Germany, a
few years ago, a distinguished biologist wrote in the Frankfurter
Zeitung that it would secure immortality for its author, the most notable
critic of the idea of immortality. And the Daily Telegraph reviewer
described the English version as a "handsome edition of Haeckel's
monumental work," and "an issue worthy of the subject and the
author."
The influence of such a work, one of the most constructive that Haeckel
has ever written, should extend to more than the few hundred readers
who are able to purchase the expensive volumes of the original issue.
Few pages in the story of science are more arresting and generally
instructive than this great picture of "mankind in the making." The
horizon of the mind is healthily expanded as we follow the search-light
of science down the vast avenues of past time, and gaze on the uncouth
forms that enter into, or illustrate, the line of our ancestry. And if the
imagination recoils from the strange and remote figures that are lit up
by our search-light, and hesitates to accept them as ancestral forms,
science draws aside another veil and reveals another picture to us. It
shows us that each of us passes, in our embryonic development,
through a series of forms hardly less uncouth and unfamiliar. Nay, it

traces a parallel between the two series of forms. It shows us man
beginning his existence, in the ovary of the female infant, as a minute
and simple speck of jelly-like plasm. It shows us (from analogy) the
fertilised ovum breaking into a cluster of cohering cells, and folding
and curving, until the limb-less, head-less, long-tailed foetus looks like
a worm-shaped body. It then points out how gill-slits and
corresponding blood-vessels appear, as in a lowly fish, and the fin-like
extremities bud out and grow into limbs, and so on; until, after a very
clear ape-stage, the definite human form emerges from the series of
transformations.
It is with this embryological evidence for our evolution that the present
volume is concerned. There are illustrations in the work that will make
the point clear at a glance. Possibly TOO clear; for the simplicity of the
idea and the eagerness to apply it at every point have carried many,
who borrow hastily from Haeckel, out of their scientific depth. Haeckel
has never shared their errors, nor encouraged their superficiality. He
insists from the outset that a complete parallel could not possibly be
expected. Embryonic life itself is subject to evolution. Though there is
a general and substantial law--as most of our English and American
authorities admit--that the embryonic series of forms recalls the
ancestral series of forms, the parallel is blurred throughout and often
distorted. It is not the obvious resemblance of the embryos of different
animals, and their general similarity to our extinct ancestors in this or
that organ, on which we must rest our case. A careful study must be
made of the various stages through which all embryos pass, and an
effort made to prove their real identity and therefore genealogical
relation.
This is a task of great subtlety and delicacy. Many scientists have
worked at it together with Professor Haeckel--I need only name our
own Professor Balfour and Professor Ray Lankester--and the scheme is
fairly complete. But the general reader must not expect that even so
clear a writer as Haeckel can describe these intricate processes without
demanding his very careful attention. Most of the chapters in the
present volume (and the second volume will be less difficult) are easily
intelligible to all; but there are points at which the line of argument is
necessarily subtle and complex. In the hope that most readers will be
induced to master even these more difficult chapters, I will give an

outline of the characteristic argument of the work. Haeckel's distinctive
services in regard to man's evolution have been:
1. The construction of a complete ancestral tree, though, of course,
some of the stages in it are purely conjectural, and not final.
2. The tracing of the remarkable reproduction of ancestral forms in the
embryonic development of the individual. Naturally, he has not worked
alone in either department.
The second volume of this work will embody the first of these two
achievements; the present one is mainly concerned with the latter. It
will be useful for the reader to have a synopsis of the argument and an
explanation of some of the chief terms invented or employed by the
author.
The main theme of the work is that, in the course of their embryonic
development, all animals, including man,