MUSEUM OF COMPARATIVE ZOOLOGY. 165 



of all others to be variable ; that authors, in their statements and opinions, 

 are widely discrepant and often contradictory ; finally, that the American 

 animal is most closely allied to the Asiatic, grading through it into the 

 European. At present there seems to be no middle ground between con- 

 sidering all as forming one circumpolar species and admitting a considerable 

 and indefinite number, since some of the so-called " varieties " seem as 

 strongly marked forms as some of the "species." If we must consider the 

 American as distinct from those of the Old World, we can hardly do less, 

 on parallel grounds, than to recognize two or more in America. It seems 

 probable that in time the greater part will be found to be not permanent 

 or uniformly transmissible varieties, but merely irregular individual va- 

 riations ; — in other words, that more than one so-called variety may be 

 represented in the same family, as has been shown is the case in the 

 foxes and wolves, and as is well known to occur in Mephitis* The com- 

 parison of a great number of specimens from many localities will be 

 necessary before we can consider the matter as satisfactorily settled. 



Since writing the foregoing, I have met with a very valuable paper on 

 the Fur-Bearing Animals of the Mackenzie's River District,! and another 

 on the Martens and Weasels of Nova Scotia ; \ I have also had an oppor- 

 tunity of comparing a large number of skins of the Siberian sable with 

 an extensive series of others from Hudson's Bay. Much additional infor- 

 mation has been derived from these sources, which tends to confirm the 

 opinion above expressed ; namely, that most of the so-called varieties 

 and species would prove to be based on seasonal and individual variations 

 of a single circumpolar species. The writer of the first of these papers, Mr. 

 Bernard R. Ross, is well known from his extensive Natural History explo- 

 rations in the boreal regions of this continent, and his experience of thirteen 

 years in this district as a successful trapper entitles his statements and 

 opinions to more than ordinary weight. He seems to have been a critical 

 observer, and in this paper adds much to our knowledge of the fur-bearing 

 animals of North America. His remarks on the seasonal changes in the 

 color and character of the fur in several species are particularly valu- 

 able. The following extracts from them explain to a great extent the 

 nature of the wide variations which, in many characters, the martens and 

 sables everywhere exhibit. 



* Seejioslen, p. 173 et seq. 



t A Popular Treatise on the Fur-bearing Animals of the Mackenzie's River District. 

 By Bernard Roc; an Ross, C. T. — Canadian Naturalist and Geologic, Vol. VI, January, 

 1861, pp. 5-36. 



{ On the Mammals of Nova Scotia, No. III. By Dr. J. Bernard Gilpin. — Transact. 

 Nova Scotia Inst, of Nat. Science, Vol. II, Part I, pp. 8- 10. 



