omplex, or, as we
should now say, it proceeded from the generalized or undifferentiated to
the specialized and differentiated. He perceived that many forms had
been subjected to what he calls degeneration, or, as we say,
modification, and that the progress from the simple to the complex was
by no means direct. Moreover, fossil animals were, according to his
views, practically extinct species, and stood in the light of being the
ancestors of the members of our existing fauna. In fact, his views,
notwithstanding shortcomings and errors in classification naturally due
to the limited knowledge of anatomy and development of his time, have
been at the end of a century entirely confirmed--a striking testimony to
his profound insight, sound judgment, and philosophic breadth.

The reforms that he brought about in the classification of the
invertebrate animals were direct and positive improvements, were adopted
by Cuvier in his _Regne animal_, and have never been set aside. We owe
to him the foundation and definition of the classes of Infusoria,
Annelida, Arachnida, and Crustacea, the two latter groups being
separated from the insects. He also showed the distinctness of
echinoderms from polyps, thus anticipating Leuckart, who established the
phylum of Coelenterata nearly half a century later. His special work
was the classification of the great group of Mollusca, which he regarded
as a class. When in our boyhood days we attempted to arrange our shells,
we were taught to use the Lamarckian system, that of Linne having been
discarded many years previous. The great reforms in the classification
of shells are evidenced by the numerous manuals of conchology based on
the works of Lamarck.

We used to hear much of the Lamarckian genera of shells, and Lamarck was
the first to perceive the necessity of breaking up into smaller
categories the few genera of Linne, which now are regarded as families.
He may be said to have had a wonderfully good eye for genera. All his
generic divisions were at once accepted, since they were based on valid
characters.

Though not a comparative anatomist, he at once perceived the value of a
knowledge of the internal structure of animals, and made effective use
of the discoveries of Cuvier and of his predecessors--in fact, basing
his system of classification on the organs of respiration, circulation,
and the nervous system.

He intimated that specific characters vary most, and that the peripheral
parts of