LAMARCK AND LAMARCKISM 29 



These modifications are transmitted by generation 

 and retained by heredity so long as new wants 

 do not intervene. 



Such is the theoretical and by far the most 

 seductive side of the philosophical work of Lamarck. 

 Let us now see how the learned naturalist of the 

 Museum succeeded in applying these principles to 

 the history of the development of the animated 

 world. 



Although Lamarck was acquainted with and 

 has described many species of fossil invertebrates, 

 he ventured seldom and seemingly against his 

 will into the field of philosophical Palaeontology. 

 It was still a question for him whether, in view 

 of the means taken by nature to assure the preserva- 

 tion of species, entire races could have been anni- 

 hilated or lost. The extinction of species only 

 seems to him admissible so far as regards the great 

 terrestrial animals, and to be then only due to the 

 active intervention of man. Nor did it seem to 

 him impossible that we might some day, in some 

 unexplored part of our planet, discover species 

 termed extinct, and even the Palaeotherium, the 

 Anoplotherium, the Megatherium, and the Mastodon 

 of Cuvier. 



If the ideas of Lamarck are thus very belated 

 compared with those of Cuvier as regards the suc- 

 cession of faunas through the geological ages, on the 

 other hand he protests with much justice against the 

 idea of universal catastrophes having annihilated 

 the majority of species over the whole surface 

 of the globe. Nature only shows us local cata- 

 strophes, such as volcanic eruptions, earthquakes, 



