BRANCH CHORD AT A ; CLASS AVES : THE BIRDS 335 



being modified for different uses, their various bones have 

 assumed different relations to each other and to the body, 

 for they are bent at directly opposite angles and the 

 attachment of muscles is different. Compare the skeleton 

 of the bird with that of the toad. (For a detailed account 

 of the skeleton of the bird see Parker's " Zootomy, " 

 pp. 182-209, or Martin and Moale's " How to Dissect a 

 Bird," pp. 102-125.) 



Life-history and habits. The English sparrow was 

 first introduced into the United States in 1850, and since 

 that time has rapidly populated most of the cities and 

 towns of the country. On account of its extreme adapt- 

 ability to surroundings, its omnivorous food-habits and its 

 fecundity it survives where other birds would die out. 

 It also crowds out and has caused the disappearance or 

 death of other birds more attractive and more useful. 

 The sparrow annually rears five or six broods of young, 

 laying from six to ten eggs at each sitting. Had it no 

 enemies a single pair of sparrows would multiply to a 

 most astonishing number. The sparrow has, however, a 

 number of enemies, most common among them perhaps 

 being the " small boy," but birds and mammals play the 

 chief part in the destruction. The smaller hawks prey 

 upon them, and rats and mice destroy great numbers of 

 their young and of their eggs whenever the nests can be 

 reached. The sparrow is omnivorous and when driven 

 to it is a loathsome scavenger, though at other times its 

 tastes are for dainty fruits. Its senses of perception are 

 of the keenest; it can determine friend or foe at long 

 range. The nesting habits are simple, the nests being 

 roughly made of any sort of twigs and stems mixed with 

 hair and feathers and placed in cornices or trees. A 

 maple-tree in a small Missouri town contained at one time 

 thirty-seven of these nests. 



