38 DISTINCTION BETWEEN SPECIES AND VARIETIES. 



15. Now, if we turn to other tribes of animals, we shall find 

 that races exist, in which the tendency to variation is so slight, 

 that differences between two animals, far less in degree than 

 those which exist between the breeds of Dogs, are quite sufficient 

 to serve as distinctions of species. Thus, among the Feline or 

 Cat tribe, the resemblance between most of the species is so great, 

 that, excepting in regard to their size, it is not easy to detect any 

 differences between their skeletons ; that of the common Cat, for 

 instance, being almost precisely a miniature representation of that 

 of the Tiger. Even in species so different in external appearance 

 as the Lion and Tiger, the form of the skull is so nearly the same, 

 that there is no constant mark by which they can be distin- 

 guished. Yet these several species, nearly allied as they seem, 

 never exhibit any tendency to assume each other's characters, or 

 to lose their own ; but preserve their respective forms, and even 

 the markings on the skin, unchanged, from generation to gene- 

 ration. The only species in which there is any decided tendency 

 to variation, is the domestic Cat; of which, as is well known, there 

 are several breeds. But these races differ much less from each 

 other, than do the different breeds of the Dog ; and the variations 

 chiefly consist in the length and colour of the hair. But in the 

 other Felines, even these characters remain so constant, that cer- 

 tain stripes and patches are repeated, generation after generation, 

 upon each individual ; and thus afford grounds for regarding as 

 distinct species, any races between which marked differences 

 exist, even of so trifling a character. These have not been sub- 

 jected to the influence of domestication, for the simple reason, 

 that they do not seem capable of it ; their ferocity not being 

 subdued by confinement, nor softened by kindness; and their 

 constitutions not being endowed with the power of adapting 

 themselves to those variations of temperature, food, habits, &c. 

 which animals that are brought into subjection to Man must 

 undergo. 



1 6. Upon grounds as trifling (in appearance at least) as these, 

 the Zoologist feels himself justified in marking out as distinct 

 species, in other groups of Animals, those which present con- 

 stant differences, however insignificant, whilst in similar cir- 



