176 CLASS MAMMALIA. 



distinct gray species. M. F. Cuvier, who describes the Gray 

 Squirrel in question, observes, in conclusion, that his ob- 

 ject is not so much to prove that the Petit-Gris does not 

 belong to the common species, as to show that the true 

 relationship of these animals is not sufficiently established, 

 and that further observations are indispensable to that 

 end. 



The Alpine Squirrel (S. Alpinus, F. Cuvier) has been 

 lately described byM. F. Cuvier. If it has been previously 

 noticed by Gesner, Aldrovandus, or Klein, it has been 

 treated as a variety of the common breed. It is certain, 

 however, that the characters which distinguish it from the 

 last-mentioned species are not accidental, nor are they the 

 effects of age, sex, or season — they have all the constancy of 

 specific characters, the young have them at their birth, and 

 the adults never change them* nor are they, according to 

 the describer of this animal, of that nature, as to be consi- 

 dered like the characters of races which generation may 

 reproduce, but which are attributable, nevertheless, to for- 

 tuitous causes, and not to the primitive organization of the 

 animal, at least we have neither sufficient examples nor ana- 

 logies in this genus to abstract the differences which dis- 

 tinguish the common Squirrel from that in question, whence 

 to infer their specific identity. 



Nature is so rich, so prodigal of her powers, so infinite 

 in means, and we are so much accustomed to see the several 

 species vary from the influence of surrounding circum- 

 stances, that we may well be surprised at finding so few 

 species of Squirrels in this part of the world, in countries 

 which seem quite favourable to the nature of these ani- 

 mals, and to their perfect development ; while in America, 

 on the other hand, under parallel degrees of latitude, a 

 comparatively large number of species of these animals is 

 to be found. 



Moreover, when we perceive, or think we perceive, any 



