THE TRANSMUTATION OF SPECIES. 249 



Holding the above opinions as to the stability of 

 species, Lamarck necessarily wholly abandoned the view 

 that the animals and plants now in existence had been 

 produced de novo, just as and where we now find them. 

 He, of course, similarly rejected the view that the animals 

 and plants of each successive geological period had been 

 created specially, en masse, for that period. He admitted 

 partial and local catastrophes ; he would hear nothing of 

 universal catastrophes. On the contrary, his views led 

 irresistibly to the belief that the animals and plants of 

 each successive period of the earth's history, including 

 the present period, had been produced by variation from 

 animals and plants previously in existence. 



Lamarck was not, however, clear as to the fact that 

 successive races of animals and plants had during the 

 progress of the ages become extinguished, and had been 

 replaced by other different assemblages of living beings. 

 He treats of this subject in a well-known chapter of the 

 ' Philosophic Zoologique,' entitled ' Des especes dites 

 perdus.' Upon the whole he is inclined to doubt if the 

 means taken by nature to conserve species and races 

 have been so inefficient and imperfect that entire groups 

 could have become extinct. He admits that many fossil 

 animals are certainly distinct from any known living 

 species. Against this, he thinks, may be set off the fact 

 that our knowledge of living animals is still very im- 

 perfect. In the case of the Pal&otheria, and other large 

 Mammals described by Cuvier from the Tertiary rocks of 

 the Paris basin, he admits that it is impossible for living 

 representatives to exist, and yet to have escaped 

 observation. As regards these he is willing to admit 



