"In spite, however, of his incessant toil, Lamarck's position continued to be most precarious. He lived by his pen, as a publisher's hack, and it was with difficulty that he obtained even the poorly paid post of keeper of the king's cabinet of dried plants. Like most other naturalists he had thus to contend with incessant difficulties during a period of fifteen years. "At length fortune bettered his condition while changing the direction of his labours. France was now under the Convention; what Carnot had done for the army Lakanal undertook to do for the natural sciences. At his suggestion a museum of natural history was established. Professors had been found for all the chairs save that of Zoology; but in that time of enthusiasm, so different from the present, France could find men of war and men of science wherever and whenever she had need of them. Etienne Geoffroy St. Hilaire was twenty-one years old, and was engaged in the study of mineralogy under Hauey. Daubenton said to him, 'I will undertake the responsibility for your inexperience. I have a father's authority over you. Take this professorship, and let us one day say that you have made zoology a French science.' Geoffroy accepted, and undertook the higher animals. Lakanal knew that a single professor could not suffice for the task of arranging the collections of the entire animal kingdom, and as Geoffroy was to class the vertebrate animals only, there remained the invertebrata--that is to say, insects, molluscs, worms, zoophytes--in a word, what was then the chaos of the unknown. 'Lamarck,' says M. Michelet, 'accepted the unknown.' He had devoted some attention to the study of shells with Bruguieres, but he had still everything to learn, or I should perhaps say rather, everything to create in that unexplored territory into which Linnaeus had declined to enter, and into which he had thus introduced none of the order he had so well known how to establish among the higher animals. "Lamarck began his course of lectures at the museum in 1794, after a year's preparation, and at once established that great division of animals into vertebrate and invertebrate, which science has ever since recognized. "Dividing the vertebrate animals--as Linnaeus had already divided them--into mammals, birds, reptiles, and fishes, he divided the invertebrates into molluscs, insects, worms, echinoderms, and polyps. In 1799 he separated the crustacea from the insects, with which they had been classed hitherto; in 1800 he established the arachnids as a class distinct from the insects; in 1802 that of the annelids, a subdivision of the worms, and that of the radiata as distinct from the polyps. Time has approved the wisdom of these divisions, founded all of them upon the organic type of the creatures themselves--that is to say, upon the rational method introduced into zoology by Cuvier, Lamarck, and Geoffroy St. Hilaire.