- 
Observations on the Cuckoo. A471 
to conclude that this is the case with all mi- 
gratory birds without exception. But to 
return to the cuckoo. Early in the ensuing 
spring, it revisits the country where it was 
bred, or seeks another equally well suited to 
its habits and necessities. If a male bird, its 
well known cry, that is now heard for the first 
time, and which I need scarcely observe can- 
not have been taught it, at once distinguishes 
its sex. Ifa female, it is solicitous after im- 
pregnation, to secure a suitable asylnm for its 
offspring ; and here, though Darwin denies it, 
the operations of instinct are most strikingly 
manifested. Without any previous instrue- 
tion, it discovers the nests of other birds, 
though it constructs none itself, by watching 
the birds build them ; and selecting such only, 
as from the size of the owners, and their 
manner of feeding, are best adapted to afford 
security to its eggs, and proper nourishment 
for its young, it lays, just when the small 
birds themselves begin to lay, a single egg in 
each, till it has produced its appropriate 
number, as if aware of the consequences 
that would ensue, were two or more eggs 
deposited in the same nest. 
Having, in this hasty sketch, shewn that 
the instinctiveness of the most remarkable 
propensities of the cuckoo admits. of direct 
