22 OUK DOIIESTIC FOWLS. 



rounded. In some, however, as the grouse 

 tribe, they are pointed ; but even in these 

 flight is not performed without considerable 

 exertion, and a rapid vibration of the wings, 

 accompanied by a loud whirring. To those who 

 have "put up" pheasants or coveys of partridges 

 this almost startling sound is familiar. 



In the gallinaceous group there is a great 

 tendency to the development of naked combs 

 and wattles, and various naked fleshy or mem- 

 branous caruncles about the head ; the fowl 

 has a comb, wattles, and a naked space on the 

 sides of the cheeks ; but in the turkey we see 

 the naked carunculated appendages much more 

 extensive. 



To the present group of birds one par- 

 ticularity in their internal structure is a 

 strong muscular gizzard, lined with a tough 

 leathery membrane. By the action of the 

 two thick muscular sides of this gizzard on 

 each other, the seeds and grains swallowed, 

 (and previously macerated in the crop, and 

 there softened by a peculiar secretion oozing 

 from glandular pores,) are ground up, or 

 triturated, in order that their due digestion 

 may take place. It is a remarkable fact that 

 these birds are in the habit of swallowing 



