It was through the endorsements of Lamarck and Geoffroy Saint-Hilaire that Cuvier was brought into this great scientific institution; Cuvier, who was later to be advanced above him in the Jardin and in public favor, and who was to break friendship with Lamarck and become the opponent of his views, and who also was to engage in a memorable debate with his other supporter, Saint-Hilaire. The portrait of Lamarck shown in Fig. 112 is one not generally known. Its date is undetermined, but since it was published in Thornton's _British Plants_ in 1805, we know that it was painted before the publication of Lamarck's _Philosophie Zoologique_, and before the full force of the coldness and heartless neglect of the world had been experienced. In his features we read supremacy of the intellect, and the unflinching moral courage for which he was notable. Lamarck has a more hopeful expression in this portrait than in those of his later years. [Illustration: Fig. 112.--Lamarck, 1774-1829. From Thornton's _British Plants_, 1805.] Lamarck Changes from Botany to Zoölogy.--Until 1794, when he was fifty years of age, Lamarck was devoted to botany, but on being urged, after the reorganization of the _Jardin du Roi_, to take charge of the department of invertebrates, he finally consented and changed from the study of plants to that of animals. This change had profound influence in shaping his ideas. He found the invertebrates in great confusion, and set about to bring order out of chaos, an undertaking in which, to his credit be it acknowledged, he succeeded. The fruit of his labors, the Natural History of Invertebrated Animals (_Historie naturelle des Animaux sans Vertèbres_, 1815-1822), became a work of great importance. He took hold of this work, it should be remembered, as an expert observer, trained to rigid analysis by his previous critical studies in botany. In the progress of the work he was impressed with the differences in animals and the difficulty of separating one species from another. He had occasion to observe the variations produced in animals through the influence of climate, temperature, moisture, elevation above the sea-level, etc.