140 BY-WAYS AND BIRD-NOTES. 
it appears to be erratic in its laying, the eggs 
in its own nest varying greatly in number and 
in development stage. 
I have collected and arranged all the ob- 
tainable facts on this subject, and my conclu- 
sions in short are: That the cuckoo of North 
America, more especially the Yellow-bill, may 
be either slowly losing or slowly gaining the 
egg-depositing or parasitic habit of the Old- 
World species ; that it is exceedingly eccen- 
tric, in connection with this habit, acting from 
the impulse of accidental necessity on account 
of an irregular fecundity. Its nest-building 
habit will not admit of its rearing a large 
brood of young; its eggs must, therefore, be 
divided among the nests of its neighbors: 
that is, whenever the over-supply comes on. 
The bird itself, as regards the two species 
(black-billed and yellow-billed) with which I am 
well acquainted, is very strangely sly, furtive, 
and erratic in all its actions, affecting a close 
observer with the impression that it is all the 
time laboring under some restrictions or lim- 
itations not common to birds in general. Its 
movements are graceful, but there is in them 
something that suggests unsubstantiality—the 
lightness that comes of an ill-baianced nature. 
Its form is elongated and so accentuated 
by its slender, curving bill and disproportion- 
ally developed tail, that it appears almost 
serpent-like at times, as it creeps with a noise- 
less gliding motion through the foliage. 
There is never any evidence of happiness in 
its actions or in the sound of its voice. On 
the contrary, the cuckoo appears to be the 
embodiment of aimlessness, restlessness, and 
unmeaning discontent. Its solemn, almost 
