Cuvier'*s Biographical Memoir of M, de Lamarck. 15 



and scales into feathers. In advancing these illustrations, we 

 have used the words of the author, that we may not be suspect- 

 ed either of adding to his sentiments or detracting any thing 

 from them. 



These principles once admitted, it will easily be perceived 

 that nothing is wanting but time and circumstances to enable a 

 monad or a polypus gradually and indifferently to transform them- 

 selves into a frog, a stork, or an elephant. But it will also be per- 

 ceived that M. de Lamarck could not fail to come to the conclusion 

 that species do not exist in nature ; and he likewise affirms, that 

 if mankind think otherwise, they have been led to do so only 

 from the length of time which has been necessary to bring about 

 those innumerable varieties of form in which living nature now 

 appears. This result ought to have been a very painful one to a 

 naturalist, nearly the whole of whose long life had been devoted 

 to the determination of what had hitherto been believed to be 

 species, whether in reference to plants or animals, and whose 

 most acknowledged merit, it must be confessed, consisted in this 

 very determination. 



However this may be, M. de Lamarck reproduced this theory 

 of Life in all the zoological works which he afterwards published; 

 and whatever interest these works may have excited by their 

 positive merits, no one conceived their systematic part suffi- 

 ciently dangerous to be made the subject of attack. It was left 

 undisturbed like his theory of Chemistry, and for the same rea- 

 son, because every one could perceive that, independently of 

 many errors in the details, it likewise rested on two arbitrary 

 suppositions ; the one, that it is the seminal vapour which orga- 

 nizes the embryo ; the other, that efforts and desires may en- 

 gender organs. A system established on such foundations may 

 amuse the imagination of a poet ; a metaphysician may derive 

 from it an entirely new series of systems ; but it cannot for a 

 moment bear the examination of any one who has dissected a 

 hand, a viscus, or even a feather. 



But his theory of chemistry and of living bodies is by no 

 means the whole that M. de Lamarck accomplished in this way. 

 In his Hydrogeology,* published in 1802, he advanced a cor- 



• Hydrogeolog}', or researches on the influence exerted hy water on the 

 surface of the terrestrial globe ; on the causes of the existence of the basin 



