ORDER PASSERES. 499 



black flycatchers, which must be separated specifically, or, at 

 least, regarded as two permanently distinct races ; the exterior 

 difference between which is, that the male of the one has a 

 white collar on the upper part of its neck, while the male of 

 the other never exhibits any such mark at any age. Both 

 have a covering which varies in colour in the course of the 

 year. At one season they are black and white, at another 

 grayish-brown and grayish-white, at a third their plumage 

 presents a mixture of all these different colours. The white 

 collar which distinguishes one of these races, is apparent only 

 during the season of reproduction, and is merely indicated 

 afterwards by a faint trait of this colour, frequently interrupted 

 by gray ; but the feathers which compose it are always white 

 from their base to beyond the middle, while in the males 

 which have no collar these feathers are gray only at their 

 origin, black in the remaining part during the summer, and 

 entirely gray after the moulting. This observation, made by 

 M. Vieillot on a dozen males, has determined him not to unite 

 these two flycatchers, either as individuals or as varieties of the 

 same species. Moreover, the same naturalist has remarked 

 that, in the collared race, male, female, and young, the first 

 remex is longer than the fourth, while in the others it is either 

 a little shorter, or of equal length. 



He adds, that differences may also be remarked in their 

 mode of life. These two species or races, are seldom found at 

 the same times, in the same places. In Lorraine, where they 

 have been most minutely observed by the Count de Riocourt, 

 the collared flycatcher alone is seen during the season of re- 

 production, while the other is at that time only on its passage 

 thither. Moreover, this last is but seldom found in that 

 country, while the former is very common. M. Vieillot says, 

 that the collared flycatcher, on the contrary, is not found in 

 the neighbourhood of Paris, but that the other is frequent 

 enough, and sometimes even propagates there. He has made 

 the same observation in Normandy, in the forest of Lyons, 



