ORDER ACCIPITRES. 139 



off the timidity which usually characterizes her, she braves 

 every danger, and dares the most unequal conflicts for the 

 safety of her young. Some birds never quit their nests with- 

 out plucking feathers from their own breasts to cover their 

 eggs ; others cover them with dry leaves ; and among some spe- 

 cies, as the pigeon, the male hatches in his turn, or brings 

 food to the female. But, as we before observed, th&re are one 

 or two exceptions to this general law of Nature. 



The period of incubation varies, not only according to the 

 species, but also the degree of temperature which the eggs 

 undergo. Cold will retard, and heat accelerate, the coming 

 forth of the young. The eggs of the tomtit take but eleven 

 days in hatching ; those of the pigeon eight-and-twenty ; hens 

 have twenty-one, and many of the scolopaces and palmipedes 

 from twenty-eight to thirty. It is said that the eggs of the 

 mergus serrator (Lath.) take even fifty-seven days. 



It is well known that eggs may be hatched by artificial heat. 



That the chick may be enabled to cut the shell in which it 

 is imprisoned. Nature has provided it with a little osseous 

 eminence on the beak, which falls soon after this operation 

 has been performed : an admirable foresight, which of itself is 

 amply sufficient to indicate the views of an allwise and intelli- 

 gent Being. 



The incubation of birds must be considered as correspond- 

 ent to the gestation of quadrupeds. Nature has imparted to the 

 females of the accipitres a larger size and greater vigour than 

 to the males, from the necessity of providing living prey for the 

 young. The females of the gallinacea, on each of whom singly 

 devolves the care of a very numerous offspring, could not pro- 

 vide for it, if their chicks were not endowed with the instinct 

 of seeking food for themselves. We find that it is towards the 

 period of the birth of the young that the mothers put in requi- 

 sition all the resources of their instinct. So much tenderness 

 and trouble lavished without compensation ; such a sublime 

 and generous self-devotion in the most urgent dangers, proves 



