12 THE TRANSFORMATIONS OF THE ANIMAL WORLD 



doubt proofs of violent upheavals in the alterna- 

 tions often noticed by him of salt and fresh water 

 deposits, these last, in general, alone containing the 

 bones of terrestrial animals. This repeated alter- 

 nation implies a displacement of the seas in several 

 directions. " The changes in the height of the 

 waters," he writes, " are not due solely to a with- 

 drawal more or less gradual, and more or less 

 general ; successive irruptions and withdrawals 

 [we should nowadays say incursions and retreats of 

 the sea] have taken place, the definite result 

 of which has been, however, a universal lowering of 

 levels." Here, again, the most scrupulous geologist 

 might subscribe to these conclusions, and would 

 have to use almost the same language, while modern- 

 izing the expressions. 



Finally, from the palaeontological point of view, 

 the sudden extinction of faunas was upheld by 

 Cuvier, with the support of proofs unimpeachable 

 in the light of the facts then known. No common 

 genus, no transitional form, connects the mammals 

 of the Paris gypsum with those of the deposits 

 containing mastodons, elephants, and hippopotami 

 which succeeded them after several invasions of 

 the sea ; no identical species connects this last 

 fauna to the species in the most recent alluvions 

 or to animals in the present world. The renewal of 

 the faunas might therefore well appear complete, and 

 the eminently positivist mind of G. Cuvier refused 

 to go beyond this rigorous fact to adopt, without 

 material proofs, the transformist speculations of 

 de Maillet or the still very nebulous hypotheses of 

 Lamarck. 



