NOTES ON THE STRUCTURE OF BIRDS. 
PENELOPE CRISTATA. 
In order to compare the structure of some of the Rasorial Birds 
with that of the Australian Menura , we give a figure and some 
notes to illustrate parts of the intestinal canal of a form belonging 
to the first, which we consider aberrant. This will be useful to 
compare with the structure of the more typical species, but espe- 
cially interesting to contrast with that of a bird nearly equal in 
size, the habits of which are very little known, but which, looking 
at its size and shape, plumage, and colonial name, was considered, 
until very lately at least, as being closely allied to the Gallinaceous 
Order. 
In the intestinal canal of Penelope cristata, the oesophagus is 
very wide and membranous : before entering the body of the bird it 
exhibits a slight dilatation analogous to a crop a, after which it 
contracts previous to forming the second glandular stomach b, 
whence it opens into a small gizzard or true stomach c. The walls 
of the wide oesophagus and almost membranous crop begin to 
thicken at the entrance of the glandular stomach, and presents at 
this part strong plicae or folds d. The walls of the glandular 
stomach e , are of more than usual thickness, and seem composed 
of a series of glands in its substance, which open interiorly by 
numerous oval points. The true gizzard is in all its parts small 
when compared with the size of the bird, or with the typical Ra- 
sores ; at the same time, it exhibits a very powerful development 
in its muscular and internal arrangements. Interiorly it enters 
from the glandular stomach, by a prominent coriaceous constric- 
tion /, and the inner surface is thickly studded with points and 
rounded elevations of the same structure, feeling to the touch rough 
and hard, and the inner lining is distributed in rounded ridges, 
which will work upon or against each other like rollers, and will 
act with great power. The muscles exterior to, or working these 
9, are of considerable strength and thickness. 
The canal terminates in a wide cloaca. At about 3. 5 from the 
extremity, it contracts rather suddenly to less than half its width, 
giving off at this point two caeca of nearly equal length, but very 
narrow in diameter, and dilating slightly at the tip, where the main 
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