272 INSTINCTS OF BIRDS. 



diction, however, may be easily reconciled, by 

 admitting, what in all probability will be thought 

 sufficiently obvious, that the dictates of the 

 understanding are frequently too feeble to resist 

 the powerful influence of instinctive impulse. 

 Several examples illustrative of this view of the 

 subject will be found interspersed through the 

 remainder of the essay. There is not any neces- 

 sity therefore for entering into a more detailed 

 consideration of it here. 



After the business of nidification is completed, 

 parturition commences, which is succeeded by 

 incubation, and as birds will frequently continue 

 to deposit their eggs in the same nest, though 

 all except one or two should be removed as fast 

 as they are laid, or exchanged for others of a 

 different size and colour ; and as they will some- 

 times, after having produced their appointed 

 number, sit upon a single egg, on the eggs of 

 other birds introduced for the purpose of experi- 

 ment, on artificial ones of chalk, or even upon 

 stones of any irregular figure ; it is plain tliat 

 the acts of depositing and incubating their eggs 

 can be ascribed to instinct only. The parental 

 offices of birds to their young, are also regulated 

 by instinctive feeling, as is evinced by their 

 bestowing the same attention on the offspring of 

 other species, when committed to their care, as 



