MUSEUM OF COMPARATIVE ZOOLOGY. 185 



black bears are now generally deemed to be but varieties and not species, 

 though so regarded by Cuvier and the earlier naturalists generally. 

 Great variations in the form of the skull in individuals from the same 

 locality not unfrequently occur, aside from the differences caused by ag^ 

 and sex. Professor Baird mentions a skull from Saranao Lake, New- 

 York, -which differs very appreciably from the ordinary type, agreeing 

 quite nearly in some respects with the Ursus arctos of Europe. Concern- 

 intr this specimen he remarks : " A large number of specimens from this 

 locality may perhaps furnish a clew to this remarkable variation, which, 

 under other circumstances, would be readily allowed as indicating a dis- 

 tinct speeus."* I some time since began to consider many of the so-called 

 specific characters drawn from the skull as of very doubtful value, from the 

 wide range of variation any considerable series of specimens from the 

 same locality, and unquestionably of the same species, usually exhibit, 

 aside from those arising from differences of age and sex. In the foxes and 

 wolves, the common bear, the different species of Mustclidce, and the larger 

 rodents, such differences are often very considerable. On this point I find 

 the following concurrent testimony from an author little liable to the charge 

 of conservatism in respect to the multiplication of specie3 or other groups. 

 Dr. J. E. Gray, of the British Museum, in his recent monograph of the 

 bears, in the Proceedings of the London Zoological Society, f thus calls 

 attention to the subject. " The examination of the series of skulls of 

 bears in the [British] Museum, like t'le examination of the series of bones 

 of the Viverridce, has strongly impressed me with the uncertainty that 

 must always attend the determination of fossil bones, or indeed of bones of 

 all animals, when we have only the skulls or other bones to compare with 

 each other. There can be no doubt that the study and comparison of the 

 bones of the different species is very important, — that the skull and teeth 

 afford some of the best characters for the distinction of genera and species; 

 but few zoologists and palaeontologists have made sufficient allowance for 

 the variations that the bones of the same species assume. In the bears, I 

 have observed that there is often more difference in skulls of bears of the 

 same species from the same locality than between the skulls of two un- 

 doubted species from very different habitats and with very different habits. 

 Thus I have the skulls of some bears the habitat of which is not certainly 

 known, which I have doubts whether they should be referred to the Thibet 

 Bear (U. torquatus), or to the North American species (U. americanns), 

 but I have referred them to the latter, as they were said to have come from 

 that country. It is the same with regard to the skull of a bear that lived 

 in the Zoological Gardens for years, which has the general form of the 

 skull and the wide palate of the European bear, but the long last grinder 



* N. Am. Mam., p. 227. t 1S64, p. 6S4. 



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