434 PHILOSOPHICAL TRANSACTIONS. [aNNO 1773. 



Linnaeus's first division of this genus have, all of them, the same additional 

 cloathing for the winter; nor is this extraordinary warmth confined merely to 

 this genus, as the noble specimen of the large white owl, which has lately been 

 presented to the r. s. from Hudson's Bay, is covered about the claws with a plu- 

 mage of perhaps an equal thickness. 



The next remarkable circumstance in this bird is, that the shafts of many of 

 the wing- feathers are black; which M. de Buffbn supposes to be only 6; whereas 

 they are 8 in the specimens from Hudson's Bay; the last 2 are indeed of a fainter 

 colour. M . de BufFon next says, that Brisson counts ] 8 feathers in the tail ; and 

 Willoughby l6; which he himself reduces to ]4. It seems however that Wil- 

 loughby's number is the more accurate; and, by examining the difference be- 

 tween the summer and winter specimens, the black feathers of the tail are found 

 covered by 2 upper ones, which in summer are brown, and in winter white. 

 Neither can Mr. B. discover, in any of the specimens, the 2 white feathers in 

 the tail, according to Linnaeus's description, rectricibus nigris apice albis, inter- 

 mediis albis, as the 2 covering feathers before-mentioned cannot, with propriety, 

 be termed intermedii, nor are they white in the summer but brown; so that 

 Linnaeus makes a circumstance, which varies with the season, to be a permanent 

 characteristic of the bird. 



M. de Buffon next supposes, that Willoughby and Frisch speak of different 

 birds under the name of lagopus; because the first says that the feet are covered 

 with soft, and the latter, with harsh and bristly feathers. The remarks however 

 of these ornithologists are easily reconciled, for, if the finger is drawn according 

 to the course of the feathers, they feel soft; and if in the contrary direction, 

 harsh and bristly. The difference also between Belon, Gesner, and Linnaeus, 

 with regard to the call of this bird, is as easily accounted for; because most male 

 birds differ from the female in this respect, and sometimes the young birds from 

 those which are full-grown. 



This naturally brings Mr. B. to show, that M. de BufFon (who has great 

 merit in other parts of his Natural History, by not unnecessarily multiplying the 

 species of animals) has, in this kind of tetrao, considered as 2 species what, 

 when properly examined, will turn out to be only the lagopus, or ptarmigan. 

 His chief reason for considering the lagopus of Hudson's Bay as being distinct 

 from the ptarmigan, arises from his asserting, that Mr. Edwards, in his descrip- 

 tion of that bird, says it is twice as large. Mr. Edwards however only considers 

 the size of the Hudson's Bay lagopus as between that of a pheasant and a par- 

 tridge, in which he is very accurate; the bird is not only evidently so to the eye, 

 but weighs 3 ounces more than a common partridge.* M. de Buffbn likewise 



* The partridge, when full grown, weighs 13 ounces, and the ptarmigan l6, — Orig. 



