ETIENNE AND ISIDORE G£OFFR0Y. J29 



Buffon, is ' so in like manner to those put forward 

 seriously of both the Geoffi-oys — for Isidore Geoffroy 

 followed his father, but leant a little more openly 

 towards Lamarck. He writes : — 



" The characters of species are neither absolutely 

 fixed, as has been maintained by some j nor yet, still 

 more, indeiinitely variable as according to others. They 

 are fixed for each species as long as that species con- 

 tinues to reproduce itself in an unchanged environ- 

 ment ; but they become modified if the environment 

 changes." * 



This is all that Lamarck himself would expect, as no 

 one could be more fully aware than M. G«6ffroy, who, 

 however, admits that degeneration may extend to 

 generic differences, t 



I have been unable to find in M. Isidore Geoffrey's 

 work anything like a refutation of Lamarck's con- 

 tention that the modifications in animals and plants 

 are due to the needs and wishes of the animals and 

 plants themselves; on the contrary, to some extent 

 he! countenances this view himself, for he says, "hence 

 arise notable differences of habitation and climate, and 

 these in their turn induce secondary differences in diet 

 Mid even in habits. % Frdm which it must fbllow, though 

 I cannot fin^d it said expressly, that the author attri- 

 butes modification in some measure to changed habits, 

 and therefore to the changed desires from which the 

 change of habits has arisen ; but in the main he appears 



• ' Hist. Nat. G^n.,' vol. ii, p. 431, 1859. 

 t ' Origin of Species,' Hist. Sketch, p. xix. 

 t ' Hist. Nat. G&.,' vol. U. p. 432. 



