80 
COW BUNTING. 
Sparrow's nest with five eggs, four and one, and the Sparrow sitting, I 
watched the nest daily. The egg of the Cow-bird occupied the centre, 
and those of the Sparrow were pushed a little up the sides of the nest. 
Five days after the discovery I perceived the shell of the Finch's egg 
broken, and the next the bird was hatched. The Sparrow returned 
while I was near the nest, with her mouth full of food with which she 
fed the young Cow-bird with every possible mark of affection, and dis- 
covered the usual concern at my approach. On the succeeding day 
only two of the Sparrow's eggs remained, and the next day there were 
none. I sought in vain for them on the ground and in every direction. 
"Having found the eggs of the Cow-bird in the nest of a Yellow- 
throat, I repeated my observations. The process of incubation had 
commenced, and on the seventh day from the discovery I found a young 
Cow-bird that had been hatched during my absence of twenty-four 
hours, all the eggs of the proprietor remaining. I had not an oppor- 
tunity of visiting the nest for three days, and on my return there was 
only one egg remaining, and that rotten. The Yellow-throat attended 
the young interloper with the same apparent care and affection as if it 
had been its own offspring. 
" The next year my first discovery was in a Blue-bird's nest built in 
a hollow stump. The nest contained six eggs, and the process of incu- 
bation was going on. Three or four days after my first visit I found a 
young Cow-bird, and three eggs remaining. I took the eggs out; two 
contained young birds apparently come to their full time, and the other 
was rotten. I found one of the other eggs on the ground at the foot 
of the stump, differing in no respect from those in the nest, no signs of 
life being discoverable in cither. 
" Soon after this T found a Goldfinch's nest with one egg of each 
only, and I attended it carefully till the usual complement of the owner 
were laid. Being obliged to leave home, I could not ascertain precisely 
when the process of incubation commenced ; but from my reckoning, I 
think the egg of the Cow-bird must have been hatched in nine or ten 
CO 
days from the commencement of incubation. On my return I found 
the young Cow-bird occupying nearly the whole nest, and the foster 
mother as attentive to it as she could have been to her own. I ought 
to acknowledge here, that in none of these instances could I ascertain 
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 be so uniformly the first hatched ? The idea of the 
egg being larger, and therefore from its own gravity finding 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 
