iga LAMARCK, HIS LIFE AND WORK 



certain of them closely approach them in some re- 

 spects, 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 articu- 

 lated and even crustaceous {crustac^s)." He does not 

 refer to the nervous system, but this is done in his 

 next work. It will be remembered that Cuvier over- 

 looked this feature of the jointed limbs, and also the 

 crustaceous-like nervous system of the barnacles, and 

 allowed them to remain among the molluscs, notwith- 

 standing the decisive step taken by Lamarck. It was 

 not until many years after (1830) that Thonipson 

 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 CirrhipMes. 

 Les Annelides. 

 Les Crustac^s. 

 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. 



