This animal is found in the northern parts of both continents. He is in shape like a common squirrel, and his external difference consists in his being larger, and the colour of his hair not being red, but of a grey more or less deep; his ears are not so hairy towards the extremity as those of our squirrels. These differences, which are constant, seem sufficient to constitute a particular species. Many authors think this species is different in Europe and America, and that the grey squirrels of the former are of the common kind, and that they change their colour with the season in the northern climates. Without denying absolutely this assertion, which does not seem sufficiently proved, we look upon the grey squirrel of Europe and America as the same animal, and as a distinct species from common squirrels, who are found in the northern parts of both continents, being of the same size, and of a red, more or less bright according to the temperature of the country.
At the same time, other squirrels of a larger size, whose hair is grey, or somewhat black, in all seasons, breed in the same latitude. Besides, the fur of the grey squirrel is more fine and soft than that of our squirrels; we are, therefore, authorised to believe that though very nearly alike, they ought to be distinguished as different species.
M. Regnard says affirmatively, that the grey squirrels of Lapland are the same animals as the French squirrels. This assertion is so positive that it would be satisfactory were it not contradicted by others; M. Regnard has written excellent dramatic pieces, but he did not give a sufficient application to Natural History, nor did he continue long enough in Lapland to see the squirrels change their colour. It is true that some naturalists, and among them Linnæus, have said, that in the north of Europe the hair of the squirrel changes colour in the winter. This may be true, for the hares, wolves, and weasels, also change their colour in those climates; but from red they grow white, not grey; and to give no other instance but that of the squirrel, Linnæus in the _Fauna Suecica_, says, _æstate ruber hieme incanus_, consequently from red he becomes white; and we do not see why this author should substitute for the word _incanus_ that of _cinereus_, which is found in the last edition of the _Systema Naturæ_. M. Klein asserts, on the contrary, that the squirrels in the vicinity of Dantzic, are red in the winter as well as in the summer, and that there are others frequently found in Poland grey and blackish, who do not change their colour any more than the red; these last also breed in Canada, and in all parts of North America, consequently we may consider the grey squirrel as an animal common to both continents, and of a different species from that of the common squirrel.