LAMARCK'S THEORY OF EVOLUTION 273 



some corner of a building, and which we may suppose 

 are occupied with consulting among themselves as to 

 the tradition, to pronounce on the duration of the 

 edifice where they occur : and that going back in their 

 paltry history to the twenty-fifth generation, they 

 should unanimously decide that the building which 

 serves to shelter them is eternal, or at least that it 

 has always existed ; because it has always appeared 

 the same to them ; and since they have never heard 

 it said that it had a beginning. Great things 

 (^grandeurs) in extent and in duration are relative.* 



" When man wishes to clearly represent this truth 

 he will be reserved in his decisions in regard to stabil- 

 ity, which he attributes in nature to the state of 

 things which he observes there, f 



" To admit the insensible change of species, and 

 the modifications which individuals undergo as they 

 are gradually forced to vary their habits or to con- 

 tract new ones, we are not reduced to the unique 

 considera^tion of too small spaces of time which our 

 observations can embrace to pei^mit us to perceive 

 these changes ; for, besides this induction, a quantity 

 of facts collected for many years throws sufificient 

 light on the question that I examine, so that does 

 not remain undecided ; and I can say now that our 

 sciences of observation are too advanced not to have 

 the solution sought for made evident. 



■ " Indeed, besides what we know of the influences 

 and the results of heteroclite fecundations, we know 

 positively to-day that a forced and long-sustained 

 change, both in the habits and mode of life of ani- 

 mals, and in the situation, soil, and cHmate of plants, 

 brings about, after a sufficient time has elapsed, a 

 very remarkable change in the individuals which are 

 exposed to them. 



* Ibid. This is repeated from the article in the Annales. 

 \ Ibid. "See my Recherches sur les Corps mvans" (Appendix, 

 p. 141). 



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