ons into
dead nature. In the anatomy of animals, as in the structure of rocks
and crystals, there were to be sought out "laws of growth" and shaping
and moulding influences which accounted for the form of the
structures. To use the technical term, he was a morphologist: one who
studied the architecture of animals not merely in a spirit of admiring
wonder, but with the definite idea of finding out the guiding
principles which had determined these shapes.

Not only was the prevailing method of investigation faulty, but actual
knowledge of a large part of the animal kingdom was extremely limited.
In the minds of most zooelogists the animal kingdom was divided into
two great groups: the vertebrates and invertebrates. The vertebrate,
or back-boned, animals were well known; comparatively speaking they
are all built upon the type of man; and human anatomists, who indeed
made up the greater number of all anatomists, using their exact
knowledge of the human body, had studied many other vertebrates with
minute care, and, from man to fishes, had arranged living vertebrates
very much in the modern order. But the invertebrates were a vague and
ill-assorted heap of animals. It was not recognised that among them
there were many series of different grades of ascending complexity,
and there was no well-known form to serve as a standard of comparison
for all the others in the fashion that the body of man served as a
standard of comparison for all vertebrates. Here and there, a few
salient types such as insects and snails had been picked out, but
knowledge of them helped but little with a great many of the
invertebrates. The great Linnaeus had divided the animal kingdom into
four groups of vertebrates: mammals, birds, reptiles, and fishes, but
for the invertebrates he had done no more than to pick out the insects
as one group and to call everything else "Vermes" or worms. The
insects included all creatures possessed of an external skeleton or
hard skin divided into jointed segments, and included forms so
different as insects, spiders, crabs, and lobsters. But Vermes
included all the members of the animal kingdom that were neither
vertebrates nor insects. Cuvier advanced a little. He got rid of the
comprehensive title Vermes--the label of the rubbish-heap of
zooelogists. He divided animals into four great subkingdoms:
Vertebrates, Mollusca, Articulata, Radiata. These names, however, only
covered very superficial resemblances among the ani