ON THE INSTINCTS OF BIRDS. 13] 
that 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 in- 
stinctive feeling, as is evinced by their bestowing the 
same attention on the offspring of other species, when 
committed to their care, as they do upon their own. 
Thus the Titlark and Hedge-Warbler manifest the 
warmest attachment to the young Cuckoos, their 
foster-nurslings, though they suffer their own pro- 
geny, ejected by the intruders, to perish from neglect 
within a short distance of the nest ; and this affection 
continues, with little diminution, till their suppositi- 
tious offspring have nearly attained their full growth : 
yet under other circumstances they would pursue and 
persecute them with the utmost rancour. 
The instinctive nature of these actions is likewise 
satisfactorily established by the fact that birds, when 
taken very young and brought up in confinement, 
not only construct nests occasionally, but also lay 
their eggs in them, which they will sit upon till 
hatched, should they prove prolific, and will then 
carefully attend to the young. An anecdote or two, 
serving more fully to corroborate the opinion advanced 
above, will not, it is hoped, be unacceptable. 
In the beginning of May 1812, having found a 
Buzzard’s nest containing a single egg, the egg was 
taken and a light-coloured stone substituted for it, 
over which a rat-trap was set. The Buzzard sat upon 
the trap a day and night, when it was discovered 
K 2 
