LAMARCK. 175 



central stem, but as branching from the roots into 

 larger and smaller stems, was first published in 

 1809. This, so far as we know, was the first of the 

 great phyletic trees, the construction of which has 

 since occupied so large a portion of the energy of 

 zoologists, and has been carried to the farthest ex- 

 treme by Haeckel. 



In his second table Lamarck derives the fishes 

 from the molluscs ; but in a third table, published 

 in 1815, while it is of the same branching character, 

 he declares that he can no longer connect the 

 vertebrates at any point with the invertebrates ! 

 He therefore places them by themselves, without 

 attempting to filiate them. The third table, there- 

 fore, represents Lamarck's latest views. 



His true conception of Phylogeny grew out of 

 his appreciation of the fact that many forms of life 

 had become extinct. He says (Philosophic Zoolo- 

 gique, Chapter 3) "Those who have carefully 

 examined large collections of species, are aware 

 how they shade into each other, and that when we 

 find species which are apparently isolated, it is only 

 because we have not yet obtained the intermediate 

 forms. ... I do not wish to say that existing 

 animals form a simple and evenly graded series, 

 but they form a branching series, irregularly gra- 

 dated, the gaps having been filled by lost forms. 

 It follows that the species which terminate each 

 branch of the series are related, upon one side at 

 least, with others which shade into them." As 



