The elimination of the barnacles or Cirrhipedes from the molluscs was a decided step in advance, and was a proof of the acute observation and sound judgment of Lamarck. He says that this class is still very imperfectly known and its position doubtful, and adds: "The Cirrhipedes have up to the present time been placed among the molluscs, but although certain of them closely approach them in some respects, they have a special character which compels us to separate them. In short, in the genera best known the feet of these animals are distinctly articulated and even crustaceous (_crustacés_)." He does not refer to the nervous system, but this is done in his next work. It will be remembered that Cuvier overlooked this feature of the jointed limbs, and also the crustaceous-like nervous system of the barnacles, and allowed them to remain among the molluscs, notwithstanding the decisive step taken by Lamarck. It was not until many years after (1830) that Thompson proved by their life-history that barnacles are true crustacea. In the _Philosophie zoologique_ the ten classes of the invertebrates are arranged in the following order: _Les Mollusques._ _Les Cirrhipèdes._ _Les Annelides._ _Les Crustacés._ _Les Arachnides._ _Les Insectes._ _Les Vers._ _Les Radiaires._ _Les Polypes._ _Les Infusoires._ At the end of the second volume Lamarck gives a tabular view on a page by itself (p. 463), showing his conception of the origin of the different groups of animals. This is the first phylogeny or genealogical tree ever published. TABLEAU Servant à montrer l'origine des differens animaux. Vers. Infusoires. . Polypes. . Radiaires. . . . . . . . . Insectes. . Arachnides. Annelides. Crustacés. Cirrhipèdes. Mollusques. . . . Poissons. Reptiles. . . . . . Oiseaux. . . . . . Monotrèmes. M. Amphibies. . . . . . . . M. Cétacés. . . . M. Ongulés. M. Onguiculés. The next innovation made by Lamarck in the _Extrait du Cours de Zoologie_, in 1812, was not a happy one. In this work he distributed the fourteen classes of the animal kingdom into three groups, which he named _Animaux Apathiques_, _Sensibles_, and _Intelligens_. In this physiologico-psychological base for a classification he unwisely departed from his usual more solid foundation of anatomical structure, and the results were worthless. He, however, repeats it in his great work, _Histoire naturelle des Animaux sans Vertèbres_ (1815-1822).