l82 LAMARCK, HIS LIFE AND WORK 



with man ; it began with the simple and ended with 

 the complex, or, as we should now say, it proceeded 

 from the generalized or undifferentiated to the spe- 

 cialized and differentiated. He perceived that many- 

 forms had been subjected to what he calls degenera- 

 tion, or, as we say, modification, and that the progress 

 from the simple to the complex was by no means 

 direct. Moreover, fossil animals were, according to 

 his views, practically extinct species, and stood in the 

 light of being the ancestors of the members of our 

 existing fauna. In fact, his views, notwithstanding 

 shortcomings and errors in classification naturally due 

 to the limited knowledge of anatomy and develop- 

 ment of his time, have been at the end of a century 

 entirely confirmed — a striking testimony to his pro- 

 found insight, sound judgment, and philosophic 

 breadth. 



The reforms that he brought about in the classifi- 

 cation of the invertebrate animals were direct and 

 positive improvements, were adopted by Cuvier in 

 his Rigne animal, and have never been set aside. 

 We owe to him the foundation and definition of 

 the classes of Infusoria, Annelida, Arachnida, and 

 Crustacea, the two latter groups being separated from 

 the insects. He also showed the distinctness of 

 echinoderms from polyps, thus anticipating Leuckart, 

 who established the phylum of Ccelenterata nearly 

 half a century later. His special work was the classi- 

 fication of the great group of Mollusca, which he 

 regarded as a class. When in our boyhood days we 

 attempted to arrange our shells, we were taught to 

 use the Lamarckian system, that of Linn6 having 



