Lamarck, the Founder of Evolution: His Life and Work

by A. S. Packard

CHAPTER XII
LAMARCK THE ZOÖLOGIST

Although there has been and still may be a difference of opinion as to the value and permanency of Lamarck’s theoretical views, there has never been any lack of appreciation of his labors as a systematic zoölogist. He was undoubtedly the greatest zoölogist of his time. Lamarck is the one dominant personage who in the domain of zoölogy filled the interval between Linné and Cuvier, and in acuteness and sound judgment he at times surpassed Cuvier. His was the master mind of the period of systematic zoölogy, which began with Linné—the period which, in the history of zoölogy, preceded that of comparative anatomy and morphology.

After Aristotle, no epoch-making zoölogist arose until Linné was born. In England Linné was preceded by Ray, but binomial nomenclature and the first genuine attempt at the classification of animals dates back to the Systema Naturæ of Linné, the tenth edition of which appeared in 1758.

Ambroise Tardieu direxit

PORTRAIT OF LAMARCK

The contemporaries of Lamarck in biological science, in the eighteenth century, were Camper (1722–89), Spallanzani (1729–99), Wolff (1733–94), Hunter (1728–93), Bichat (1771–1802), and Vicq d’Azyr (1748–94). These were all anatomists and physiologists, the last-named being the first to propose and use the term “comparative anatomy,” while Bichat was the founder of histology and pathological anatomy. There was in fact no prominent systematic zoölogist in the interval between Linné and Lamarck. In France there were only two zoölogists of prominence when Lamarck assumed his duties at the Museum. These were Bruguière the conchologist and Olivier the entomologist. In Germany Hermann was the leading systematic zoölogist. We would not forget the labors of the great German anatomist and physiologist Blumenbach, who was also the founder of anthropology; nor the German anatomists Tiedemann, Bojanus, and Carus; nor the embryologist Döllinger. But Lamarck’s method and point of view were of a new order—he was much more than a mere systematist. His work in systematic zoölogy, unlike that of Linné, and especially of Cuvier, was that of a far higher grade. Lamarck, besides his rigid, analytical, thorough, and comprehensive work on the invertebrates, whereby he evolved order and system out of the chaotic mass of forms comprised in the Insects and Vermes of Linné, was animated with conceptions and theories to which his forerunners and contemporaries, Geoffroy St. Hilaire excepted, were entire strangers. His tabular view of the classes of the animal kingdom was to his mind a genealogical tree; his idea of the animal kingdom anticipated and was akin to that of our day. He compares the animal series to a tree with its numerous branches, rather than to a single chain of being. This series, as he expressly states, began with the monad and ended with man; it began with the simple and ended with the complex, 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 Règne 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 Cœlenterata 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 Linné 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 Linné, 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.