274 NOTES ON THE 
frequently the sparrow or thrushes. I believe that the Cow- 
bird is without the slightest preference as to what, or whose 
nest receives her mysterious deposit, but her instincts have 
taught her not to take such liberties with the nests of rapaci- 
ous, nor pugnacious species, and as a matter of course the 
unwelcome responsibility falls more commonly upon the weak 
and timid. The thrushes therefore ordinarily escape, and 
most of the vireos do so next in frequency, while the tiny 
warblers, and the less vigilant sparrows, bear the imposition 
more uniformly. Notably, the period of incubation for this 
species is a little less, than for any one of those which are 
thus imposed upon, thus increasing the probabilities of the 
maintenance of the species. One of the most comical spec- 
tacles ever falling under my observation in bird-life, has been 
the appearance of a young Cowbird nearly large enough to 
take to its wings, still sitting on (in was impossible) the nest 
of the Maryland Yellow-throat, and the female of that diminu- 
tive species in the act of feeding it. The tiny excavation 
could scarcely afford room for its feet, to say nothing of its body, 
and with its feathers fluffed so much as to double its apparent 
size, the mouth extended to its utmost, while the midget foster 
mother, at the hazard of being swallowed herself bodily, 
plunging her morsels far down the abyssal throat of the 
ungracious usurper, who has unavoidably destroyed the 
mothers own birdling in the process of its development. 
Let that species of birds which has no foundlings to rear, 
question this strange and exceptional provision of a beneficent 
Creator for the perpetuation of another species. Great rules 
are often revealed by their exceptions. The birds have no 
decalogue. What poor little bird-mother, so long imprisoned 
by her duties in obedience to the demands of her maternal 
instincts, may not justly envy this one, which has all of the 
pieasures, and none of the sacrifices of bird-life, except the 
agonizing anxieties of the brief moment spent in extruding her 
egg into another birds nest? 
From all that I have learned from personal observations, I 
conclude that the Cowbird lays about the same number of 
eggs as the average of its family. It is not uncommon to 
find two in the same nest, and only a little less so to find three. 
I have recorded two instances of four, and one of five. Itis 
by no means certain in any case where more than one is found 
that the same female deposited all of them. Indeed it is more 
presumptive that if her instincts should send her to the same 
