THE WHEATEAR. 363 



tion, as a general principle, that which the authorities 

 have alleged with regard to the cuckoo ; and we are 

 very much inclined to regard it as an universal law of 

 the feathered tribes, that this accumulation of heat and 

 the disposition to get rid of it by the act of incubation, 

 always follows the laying of a number of fecundated 

 eggs, greater or less according to the species and habits 

 of the bird. We have seen that in the case of many 

 birds, it affects the male also ; for we are not to sup- 

 pose that he reasons about the harm that would befal 

 the eggs in the cooling, because the young males do it 

 the very first hatch ; and, if one were to suppose that 

 birds were all Newtons in philosophy, that is a conclu- 

 sion at which they could no more arrive by reasoning, 

 without experience, than the reader can tell whether 

 tzaggitichaqui be black or white, soft or hard, or whe- 

 ther it would or would not burn, if thrown into a 

 pitcher of water. 



During the heat of the day, the male wheatear takes 

 possession of the nest, the female having come out at 

 his call. It is probable that he then sleeps for part of 

 the time ; as, about two o'clock on a warm day, he is 

 more easily captured on the nest than the female. 

 Exercise, more than food, seems to be the object that 

 the female needs by her relief, because in the morning 

 and the evening the male feeds her abundantly. No 

 doubt she picks up ants and catches a few flies ; but 

 she seems, for the greater part of the time, to return 

 the assiduity of her partner's watch ; and when they 

 " change the guard" from male to female, or from 

 female to male, there is a chatter of recognition, as if 



