ibing
new species appealed very little to him. He had none of the
collector's passion for new species; his interest in a creature being
not whether or no it was new to science, but what general problems of
biology its structure helped to elucidate. While he assisted in the
routine work of determining the zooelogical position of the fossils
sent in to the museum by the Survey, he carried investigations much
farther than the duties of the post required when interesting
zooelogical problems arose. His earliest notes were written in
association with his colleague, and consisted of technical
descriptions of some small fossils from the Downton Sandstones which
were supposed to be fish-shields. The peculiarities of structure
presented by these aroused his interest, and he began an elaborate
series of investigations upon palaeozoic fishes in general. Earlier
zooelogists, such as the great Agassiz, had devoted most of their
attention to careful and exact description of the different fossil
fishes with which they became acquainted. Huxley at once began to
investigate the relations that existed among the different kinds of
structure exhibited in the different fish. He laid down the lines upon
which future work has been conducted, and, precisely as he did in the
case of molluscs, he started future investigators upon lines of
research the ends of which have not yet been reached. His work upon
_Devonian Fishes_, published in 1861, threw an entirely new light upon
the affinities of these creatures, and still remains a standard work.

He made a similar, although less important, series of investigations
upon some of the great extinct Crustacea; but, perhaps, his most
important palaeontological work was done later, after he had been
convinced by Darwin of the fact of evolution. In 1855 he had expressed
the opinion that the study of fossils was hopeless if one sought in it
confirmation of the doctrine of evolution; but five-and-twenty years'
continuous work completely reversed his opinion, and in 1881,
addressing the British Association at York he declared that "if
zooelogists and embryologists had not put forward the theory, it would
have been necessary for palaeontologists to invent it." In three
special groups of animals his study of fossils enabled him to assist
in bridging over the gaps between surviving groups of creatures by
study of creatures long extinct. He began to study the structure of
the Labyrinthodonts, a group of extinct