ETIENNE AND ISIDORE GEOFFROY. 329 



Buffou, is so in like manner to those put forward 

 seriously of both the Geoffreys for Isidore Geoffrey 

 followed his father, but leant a little more openly 

 towards Lamarck. He writes: 



"The characters of species are neither absolutely 

 lixed, as has been maintained by some ; nor yet, still 

 more, indefinitely 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. Geoffrey, who, 

 however, admits that degeneration may extend to 

 generic differences.! 



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 

 and even in habits, t From which it must follow, though 

 I cannot fikd 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. Gen.,' vol ii. p. 431, 1859. 

 I ' Origin of Species,' Hist. Sketch, p. xix. 

 J ' Hist. Nat. Gen.,' vol. ii. p. i'6'2. 



