196 COW BUNTING. 
Iascertain exactly the time required to hatch the Cow Bird’s eggs, and 
that, of course, none of them are decisive; but is it not strange that 
the egg of the intruder should beso uniformly the first hatched? The 
idea of the egg being larger, and therefore, from its own gravity, find- 
ing the centre of the nest, is not sufficient to explain the phenomenon ; 
for in this situation the other eggs would be proportionably elevated 
at the sides, and therefore receive as much or more warmth from the 
body of the incumbent than the other.* This principle would scarcely 
apply to the eggs of the Blue-Bird, for they are nearly of the same 
size; if there be any difference, it would be in favor of the eggs of 
the builder of the nest. How do the eggs get out of the nest? Is it 
by the size and nestling of the young Cow Bird? This cannot al- 
ways be the case; because, in the instance of the Blue-Bird’s nest in 
the hollow stump, the cavity was a foot deep, the nest at the bottom, 
and the ascent perpendicular ; nevertheless, the eggs were removed, 
although filled with young ones. Moreover, a young Cow-Pen Finch 
is as helpless as any other young bird, and'so far from having the 
' power of ejecting others from the nest, or even the eggs, that they are 
sometimes found on the ground under the nest, especially when the 
nest happens to be very small. I will not assert that the eggs of the 
builder of the nest are never hatched; but I can assert that I have 
never been able to find one instance to prove the affirmative. If all 
the eggs of both birds were to be hatched, in some cases the nest 
would not hold half of them; for instance, those of the Sparrow or 
Yellow-Bird. I will not assert that the supposititious egg is brought 
to perfection in less time than those of the bird to which the nest be- 
longs; but, from the facts stated, Iam inclined to adopt such an opin- 
ion. How are the eggs removed, after the accouchement of the spu- 
rious occupant? By the proprietor of the nest, unquestionably ; for 
this is consistent with the rest of her economy. After the power of 
hatching them is taken away by her attention to the young stranger, 
the eggs would be only an encumbrance, and therefore instinct 
prompts her to remove them. I might add that I have sometimes 
found.the eggs of the Sparrow, in which were unmatured young ones, 
lying near the nest containing a Cow Bird, and therefore I cannot re- 
sist this conclusion. Would the foster-parent feed two species of 
young at the same time? I believe not. I have never seen an in- 
stance of any bird feeding the young of another, unless immediately 
after losing her own. I should think the sooty-looking stranger would 
scarcely interest w mother, while the cries of her own offspring, al- 
ways intelligible, were to be heard. Should such a competition ever 
take place, Tvl the stranger would be the sufferer, and probably 
the species soon become extinct. Why the ler nature conservatrir 
should decide in favor of the surreptitious progeny, is not for me to 
determine. : 
“ As to the vocal powers of this bird, I believe its pretensions are 
very humble, none of its notes deserving the epithet musical. The 
sort of simple, cackling complaint it utters at being disturbed, consti- 
\ 
* The ingenious writer seems not to be aware that almost all birds are in the 
habit, while sitting, of changing the eggs from the centre to the circumference, and 
vice versa, that all of thet\ may receive an equal share of warmth. 
