268 On the Question — Is there Identity between the 



viduals of which it embraces. It is particularly among the 

 less complicated beings in the vegetable and animal king- 

 dom that this persistence is most evident, and extends to a 

 very great number of generic sections. 



We have considered a species as a type easy to seize, and 

 the determination of which can give rise to no uncertainty. 

 This, however, is far from being the case. In truth, the 

 specific characters, even among living species which we mav 

 be said to have continually under our eye, are essentially 

 variable, and it is often difficult to appreciate their true 

 value. 



If, then, we submit the vegetable and animal species, ad- 

 mitted into our catalogues, to a strict and complete revision, 

 we may affirm, without fear of error, that the number would 

 be singularly reduced. If we do the same with regard to the 

 species of the old creations which have been considered iden- 

 tical with the existing races, we will perceive how little foun- 

 dation there is for the analogies by means of which they are 

 associated. This truth would become more evident still if 

 the fossil species presented themselves to us with the whole 

 of their characters unimpaired, for we would then perceive 

 differences of which we can form no idea in the imperfect 

 state of their preservation. 



When we examine the whole of the ancient creations, and 

 consider how imperfect are the remains by means of which 

 we endeavour to attain to their specific determinations, we 

 are rather disposed to regard these determinations as provi- 

 sionary than as expressing absolute certainty. Probably the 

 analogies, by aid of which endeavours have been made to 

 approximate certain species of the ancient world to those of 

 the present, are not so real as they have been supposed ; 

 at least they do not rest on the positive knowledge of their 

 characters, since the greater part of these have disappeared 

 in the fossil races. 



Accordingly, in consequence of the disappearance of these 

 specific characters, certain ancient species have been assimi- 

 lated to the living races, an association which certainly would 

 never have been made if the former had been known to us 

 in their perfect state. The greater part of those respecting 



