NATURAL HISTORY. 271 



" The careful hen 



Calls all her chirping family around, 

 Fed and defended by the fearless cock, 

 Whose breast with ardour flames, as on he walks, 

 Graceful, and crows defiance." THOMSON. 



ORDER V. RASORES. 



853. Why is the order rasores so called? 



From radoj to scrape or scratch, the birds of this order compre- 

 hending the gallinaceous tribe being distinguished by their habit 

 of scraping the earlh, to obtain food. 



854. They are omnivorous; living equally upon seeds, grains, and insects. It is 

 to this order that most of our domestic birds, the feathered tenants of the farm- 

 yard, belong; and also most of those unreclaimed by man, celebrated for the 

 excellency of their flesh, as the grouse, partridge, quail, and pheasant. 



855. Why do gallinaceous and other birds pick up small 

 stones, bits of shells, &c., and gravel, which are afterwards 

 found embedded in their gizzards? 



The gizzard is a fleshy stomach, the substance of which con- 

 sists of a strong muscle ; the dark part of the gizzard being the 

 muscle, and the shining part of it the tendon to which the 

 muscular fibres are attached Birds pick up small fragments of 

 stone, which pass with the grain to the gizzard, and there become 

 the meads of grinding the food upon which the birds subsist. 



856. There are two muscles, with a central tendon ; it is what anatomists call a 

 digastric, or double-bellied stomach. 



The cavity within this muscle is lined with a dense, rough, insensible coat, and 

 there are always to be found contained in it small stones, generally of quartz, if it 

 be within the reach of the bird. 



The grains are mixed with these portions of stone ; and if we place our ear close 

 to the bird, we may hear the grinding motions going on as distinctly as the 

 noise of the horse's jaws in a manger. 



In fact, this digastric muscle, or gi/zard, is equivalent to the muscles of the jaws, 

 and the pebbles are a fair equivalent to the teeth, with this advantage, that when 

 they are ground down, the instinct of the bird provides more.* 



857. In what respects do the gallinaceous birds resemble 

 ruminating animals ? 



By a peculiar arrangement, the food taken up by the bill of 

 Notes to raJey's " Nat. Theology," by Sir Charles Bell. 



