498 
STOMACH OF BIRDS. 
which eject or disgorge innutritious matter unavoidably taken in, such as 
feathers, fur, bones, &c., belong to the second class ; as is conspicuous in 
the falcon, (^Falconidce^ lu^Acu,') and owl, (^Strigidce^ Leach,) and 
others that feed on fish. Granivorous birds seem to possess a power of 
retaining the small stones taken into the gizzard, or evacuating them 
when they become polished and less useful, but cannot disgorge them. 
In a state of nature the quantity of gravel taken in must be regulated, 
no doubt, by the sensation of the stomach ; but, extraordinary as it may 
seem, in domesticated animals those instinctive faculties are deranged. 
We have known instances where the whole cavity of the gizzard has 
been filled with gravel stones. We once remember part of a brood of 
young ducks, half grown, taking in such a quantity of gravel, as not only 
filled the gizzard but the craw, and even the gullet ; they soon after 
died. Many species of birds possess a reservoir for food, called a craw, 
or crop, which seems to answer the same purpose as the first stomach 
in ruminating animals. Here it is that the food is softened and pre- 
pared for the stomach, or carried to the young. 
*An author in the Philosophical Transactions for 1810, maintains 
that grass requires the strongest digestive powers ; but it is probable 
that, in ruminating animals, by a second mastication, the food is better 
prepared, by its extreme comminution, to yield more expeditiously its 
nutrimental contents than can be effected in the stomach of a horse, 
who has not the power of grinding his food a second time, the masti- 
cation of which is imperfectly performed, and coarsely submitted to the 
organs of digestion. Comminution of graminous food appears to be more 
essential, in the opinion of this author, than any other power nature 
has assigned for the purpose of digestion. With this view, he seems to 
have examined the gizzard of such birds as are in the habit of grazing, 
in order to compare them with the same organ belonging to birds that 
are not considered as graminivorous ; and we are told a marked distinc- 
tion appeared between the goose and the turkey. We are informed the 
stomach of the turkey is altogether less muscular ; its parts appear to 
possess less motion on each other, and do not come in contact ; whereas, 
in the goose, the muscular fasciculi are peculiarly powerful, and the 
opposite sides move on each other, and rub down the food, very much 
like the manner in which this is done by the grinding teeth of rumi- 
nating animals. 
With all due deference to the professional abilities of this writer, we 
must take leave to remark, that the comparison between the two birds 
in question is by no means conclusive, since they are both equally gra- 
minivorous and granivorous ; for the turkey by nature, in its native 
