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, Leach,) 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 



