REV. W. HINGES ON CTGNTJS PASSMOBI. 299 



tially correct) in supposing the two forms of sternum before me 

 to be both mature, and consequently belonging to different 

 species ; but the doubt is now, I think, decided. During the 

 past winter a female Trumpeter Swan with a very young male (a 

 cygnet of the year) were shot in the immediate neighbourhood of 

 this city. They were examined by me, and their sterna are be- 

 fore me. 



The female, a mature bird, had a sternum exactly resembling 

 that which I previously possessed (fig. 7 of the sketches accom- 

 panying my paper), proving the peculiarity to be neither a mark 

 of sex nor an unusual exceptional case. The young male had the 

 foxy colour on the head and neck which is characteristic of Cygnus 

 buccinator, but (as might have been anticipated from other cases 

 of the kind) with the colour stronger and more extended than in 

 the old bird, thus differing strikingly from C. Passmori. His 

 sternum is considerably longer than that of my largest C. Pass- 

 mori, a little longer even than that of the female accompanying him ; 

 yet the trachea is in an early stage of development, the bone on 

 the inner posterior face of the sternum not yet appearing, and 

 the knob close to the vertical bone only equalling the height of 

 the ridge of that bone, instead of rising, as in the mature bird, 

 about an inch above it. In the specimen of G. buccinator previ- 

 ously examined the bony enlargement containing the curve of the 

 trachea almost concealed the posterior sinuses of the sternum, as 

 noticed in my former paper ; but in the young bird we find them 

 deeper and more elongated in form than in C. Passmori ; and even 

 after the formation of the bone, this difference may be observed 

 by careful examination. On the whole, this young bird may be 

 regarded as proving that C. Passmori is not the mere young of 

 C buccinator, from which, as well as from the old bird, it differs 

 in size, weight, colouring, and the other characters pointed out, 

 even the sternum difiering before the trachea assumes the pecu- 

 liar full-grown appearance. But there is another point settled 

 by the additional specimens. I have now before me, both in the 

 young and mature condition, the bronchial tubes of the two 

 species, those of the true buccinator having been, as I stated, 

 destroyed in. the former specimen, and the extent and constancy 

 of the differences reported being then uncertam. I can now- 

 state that, in G. Passmori, the lower portions of the bronchial 

 tubes are separate and comparatively little swelled, the upper 

 tubular parts being nearly parallel; whilst, in G. buccinator, the 

 greatly swelled and enlarged lower portions adhere together, the 



