VERTEBRATA: AVES. 613 



for scratching (fig. 338, A). The food of the Scratchers or 

 Gallinaceous birds consists chiefly of hard grains and seeds, 

 and in accordance with this they have a capacious crop and 

 an extremely strong and muscular gizzard. They mostly 

 nidificate, or build their nests, upon the ground, and the more 

 typical members of the order are polygamous. The males take 

 no part in either nidification or incubation, and the young are 

 generally " precocious," being able to run about and provide 

 themselves with food from the moment they quit the egg. 

 The young of the Pigeons and Doves, however, are brought 

 forth in a comparatively helpless condition. The wings in the 



A ^"^ 

 Fig- 338. Rasores. A, Foot of Fowl (Callus Bankiva) ; B, Head of Guinea-fowl. 



majority of the Rasores are more or less weak, and the flight 

 is feeble and accompanied with a whirring sound. Many of 

 the Pigeons, however, are capable of very powerful and sus- 

 tained flight. 



The order Rasores is divided into two sub-orders, called re- 

 spectively the Gallinacei and the Columbacei, or sometimes, 

 from the characters of the sounds which they utter, the Clama- 

 tores and the Gemitores. 



Stib-order i. Gallinacei or Clamatores. This sub-order com- 

 prises the typical members of the order Rasores, such as the 

 common Fowls, Turkeys, Partridge, Grouse, Pea-fowl, and a 

 number of allied forms. Its characters are therefore those 

 of the order itself, but it is especially distinguished from the 

 Columbacei by being less fully adapted for flight. The body is 

 much heavier, comparatively speaking, the legs and feet are 

 stronger, and the wings shorter and less powerful. On the 

 whole, therefore, these birds are worse fliers than the Colum- 

 bacei, and are better adapted for living upon the ground. The 

 hallux (fig. 339, A) is elevated above the anterior toes, and 

 merely touches the ground in walking. The back of the 

 tarsus, too, is usually furnished in the males with a spur 

 (calcar\ which is used as an offensive weapon, and has some- 



