On one group he was a little prepared, but it was by accident; a self-sacrifice to friendship was the cause.

For it was both to please his friend Bruguiere as well as to penetrate more deeply into the affections of this very reserved naturalist, and also to converse with him in the only language which he wished to hear, which was restricted to conversations on shells, that M.de Lamarck had made some conchological studies.

Oh, how, in 1793, did he regret that his friend had gone to Persia! He had wished, he had planned, that he should take the professorship which it was proposed to create.

He would at least supply his place; it was in answer to the yearnings of his soul, and this affectionate impulse became a fundamental element in the nature of one of the greatest of zooelogical geniuses of our epoch." Once settled in his new line of work, Lamarck, the incipient zooelogist, at a period in life when many students of less flexible and energetic natures become either hide-bound and conservative, averse to taking up a different course of study, or actually cease all work and rust out--after a half century of his life had passed, this rare spirit, burning with enthusiasm, charged like some old-time knight or explorer into a new realm and into "fresh fields and pastures new." His spirit, still young and fresh after nearly thirty years of mental toil, so unrequited in material things, felt a new stimulus as he began to investigate the lower animals, so promising a field for discovery.
He said himself: "That which is the more singular is that the most important phenomena to be considered have been offered to our meditations only since the time when attention has been paid to the animals least perfect, and when researches on the different complications of the organization of these animals have become the principal foundation of their study.

It is not less singular to realize that it was almost always from the examination of the smallest objects which nature presents to us, and that of considerations which seem to us the most minute, that we have obtained the most important knowledge to enable us to arrive at the discovery of her laws, and to determine her course." After a year of preparation he opened his course at the Museum in the spring of 1794.