146 THE STORY OF BIRD-LIFE. 



up as follows by Prof. Newton appear to be 

 these : " Ostriches commonly, and especially in 

 the breeding-season, live in companies of not 

 more than four or five, one of which is a cock 

 and the rest are hens. All the latter lay their 

 eggs in one and the same nest — a shallow 

 pit scraped out by their feet, with the earth 

 heaped around to form a kind of wall against 

 which the outermost circle of eggs rests. As soon 

 as ten or a dozen eggs are laid, the cock begins 

 to brood, always taking his place on them at 

 nightfall surrounded by his wives, while by day 

 they relieve one another, more it would seem to 

 guard their common treasure from jackals and 

 small beasts-of-prey than directly to forward the 

 process of hatching, for that is often left wholly 

 to the sun. . . ." 



This hatching by artificial heat is carried to 

 its farthest by the curious Australasian mound- 

 builders or megapodes, allies of the game-birds. 



These build no nest, neither do they brood 

 over the eggs to hatch them out like other birds, 

 but leave this to the heat of the sun, as is done 

 by reptiles. The megapodes of the Solomon 

 Islands and of Celebes scratch out a hole about 

 two feet deep in the hot sand, deposit an egg^ 

 cover it up, and leave it to the genial warmth 

 of the sun to bring it to life. 



In Celebe=5, much of the sand is of volcanic 

 origin, and black, and is chosen on this account 

 by the megapodes in preference to the white 

 sand. Therein they show great sagacity, in- 

 asmuch as this absorbs much heat during the 

 day, and loses comparatively little at night. 



