GOLDEN-EYE DUCK. 325 
meter, its lateral muscles very large, and upwards of half an inch thick ; 
its epithelium rugous. The intestine is 6 feet 1 inch long, its diameter 
varying from 5 twelfths to 4 twelfths ; the rectum 4 inches long; the 
coeca 31 inches in length, their greatest diameter 24 twelfths. The con- 
tents of the stomach a soft mass of a reddish colour, in which are dis- 
tinguished small mussels and remains of fishes, with some vegetable 
fibres. 
' The trachea is 9 inches long, for 4 inches narrow, its diameter 
being about 43 twelfths, and its rings, which are 60 in number, carti- 
laginous ; it then forms an ovato-oblong expansion, which, when drawn 
out, is 24 inches long, and 1 inch in breadth, and is formed of ossified 
and flattened rings, narrower behind, placed obliquely, and about 30 in 
number ; it then contracts to a diameter of 5 twelfths, and has 16 free 
rings, but below this the rings, 25 in number, become united or blend- 
ed, and gradually expand into a vast irregular cavity, having a broad 
bony frame in front, membranous behind, and separating to the dis- 
tance of 1 inch, the bronchi, which are large, the right one much 
larger and longer than the left, and composed of 20 rings, all of which 
are almost complete and cartilaginous, excepting the two upper. The 
rings of the left bronchus, also about 20, are more incomplete. 
Now for conjectures. These enormous dilatations are intended 
‘for strengthening the voice. But the voice is not strong in this duck, 
Well, then, they are receptacles of air, to enable the bird to keep 
longer under water. But the bird does not keep longer under water 
than many other ducks, and besides, the female, which has no such di- 
latations, dives as well as the male. 
One use at least is this. A comparison of the windpipe of an 
American Golden-eye, with those of two Scotch ones, shews that the 
so-called Clangula Americana, is in this respect precisely similar to the 
— Olangula chrysophthalma. Their digestive organs are also the same ; 
and American skins compared with European skins, exhibit no diffe- 
rences of the slightest importance. Some individuals, especially males, 
have much larger bills than others, but this happens in the birds of 
both countries, and the Golden-eye is not singular in this respect. 
Clangula Americana, therefore, requires a better elucidation than the 
_ appendage of a “* Nob,” before it can be admitted as a species. 
