152 BIRD BEHAVIOUR 



I was afterwards told that she had laid none at all 

 the next. ' 



What may be called voluntary overlaying is 

 rather apt, however, to occur in captive birds ; 

 the Californian Quail {Lophortyx californicus) is 

 particularly liable to it. It may even occur in 

 Nature ; thus, a specimen of the Indian Nukta or 

 Comb-Duck {Sarcidiornis melanonota) has been 

 captured on a regular deposit of eggs, tier after 

 tier, amounting to forty in number; and as she 

 was very emaciated, and one of the eggs was very 

 small, presumably her last, she had no doubt laid 

 the lot. 



Such cases as these, and exceptional Turkey, hens 

 that lay a hundred eggs, show us how our high- 

 laying races of Fowls and Ducks have been origin- 

 ated ; they began a long time ago, since Aristotle 

 speaks of every-day layers. Birds may deposit 

 their batch of eggs at the rate of one egg a day, or 

 lay at intervals of two or more days ; the rule is 

 not constant for tlie same group, since the Pigeon 

 deposits her second egg two days after laying her 

 first, and the Collared Dove lays her pair on con- 

 secutive days. With hens and Turkeys, too, every- 

 day or intermittent laying varies individually. 



Most birds, although keeping about the nest, do 

 not begin to sit till they have got the full number ; 

 the rule appears to be universal among those which 

 have active young, since their broods all come off 

 at once, but birds may make a mistake or get 

 impatient, and go off with a partial brood, leaving 



