s is to be laid, that morphology has to do with animal form as
something _given_ by Nature, that though it follows out the changes
taking place during the development of an animal and tries to explain
them, it does not enquire after the conditions whose necessary and
physical consequence this form actually is" (p. 24). He expressed indeed
a pious hope (p. 25) that physiology might one day be so far advanced
that it could attempt with some hope of success to discover the
physico-chemical determinism of form, but this remained with him merely
a pious hope. Reichert, in his _Bericht_, applied to the rather wild
theorisings of the physiologist Ludwig the same clear commonsense
criticism that he bestowed on the other "atomists."

It would take too long to describe the great development that
materialistic physiology took at this time, and to show how the
separation of morphology from physiology, which originally took place
away back in the 17th century, had by this time become almost absolute.
The years towards the end of the first half of the century marked indeed
the beginning of the classical period as well of physiology as of
dogmatic materialism. Moleschott and Buchner popularised materialism in
Germany in the 'fifties, while Ludwig, du Bois Reymond and von Helmholtz
began to apply the methods of physics to physiology. In France, Claude
Bernard was at the height of his activity, rivalled by workers almost as
great. The doctrine of the conservation of energy was established about
this same time.

Between the cell-theory on the one side, and physiology on the other, it
was a wonder that morphology kept alive at all. The only thing that
preserved it was the return to the sound Cuvierian tradition which had
been made by many zoologists in the 'thirties and 'forties. It is a
significant fact that this return to the functional attitude coincided
in the main with the rise of marine zoology, and that the man who most
typically preserved the Cuvierian attitude, H. Milne-Edwards, was also
one of the first and most consistent of marine biologists. Milne-Edwards
describes in his interesting _Rapport sur les Progres recents des
Sciences zoologiques en France_ (Paris) 1867, how "About the year 1826,
two young naturalists, formed in the schools of Cuvier, Geoffroy and
Majendie, considered that zoology, after having been purely descriptive
or systematic and then anatomical, ought to take on a more physiological
character; they consider