60 
THE COLUMBIDJi:. 
without exception, short wings, the hand bones, collectively, being shorter than 
the humerus. 
The sternum of Pigeons has one moderately deep notch or emargination on its 
exterior edge, and one shallow one, or in many instances only a small hole 
pierced near the posterior edge.—The sterna of all Gallinaceous birds have two 
very deep emarginations on each side. 
The keel in Pigeons is very much rounded off at its anterior extremity, is of 
great depth, and extends as far forwards as the anterior point of the sterna.— 
In Gallinaceous birds the keel approaches much nearer to a straight line, is of 
less proportional depth, and terminating generally in a p oint; though the 'Cmcidm 
certainly have the keel more resembling that of the Pigeon, than the other classes. 
The keel seldom exceeds two-thirds the length of the sternum ; in some instances 
it is not much more than half the length, and it never reaches nearly to its an¬ 
terior extremity. , 
In Pigeons the hind toe is placed at the bottom of the tarsus, on a level with 
the front toes, as obtains in the Insessores^ and the front toes have no connecting 
membrane.—Gallinaceous birds (I believe), with the single exception of the 
Guan, have the hind toe situated higher than the front toes, which are always 
united by a membrane. 
’Ih.Q ,Columbid€B have the heart proportionably larger than the Rasores,-— 
Cuvier says, when speaking of the intestines of birdsBirds generally have 
two c®ca^ which insert themselves on each side of the intestinal canal; in om¬ 
nivorous and graminivorous birds, they are usually long and of great size."* Here 
I think he speaks rather too generally. I have examined several species and 
some genera of the Columbidm^ which are peculiarly graminivorous; most of them 
entirely want the caeca | and where they exist, they are so small as to be nearly 
microscopic. 
In all the Rasores which I have examined, the caeca are considerably developed ; 
in the Red Grouse these organs are very large,—^affording a wise and seasonable 
provision for those privations to which the birds are subjected during periods of 
continuous snow. 
I have no intestines of the Curasow, the Guan, or the Crowned Pigeon ; hut 
as the two former approach the other Rasores so nearly in the form of their 
skeletons, I assume that their caeca and crops would follow the same type; and as 
the skeleton of the Crowned Pigeon so nearly resembles that of the typical 
ColumbidiEf I presume that, like them, it will want the cseca.—I regret not 
having preserved the intestines of these birds; hut when I began preparing skele¬ 
tons of birds, I was so occupied with the bony structure, that I attended to no 
other trait of their anatomy. Such, I believe, is often the case on taking up a 
new subject; we know not what is likely to be useful, and often throw away 
