432 
Brewer’s Remarks on 
but with it, her own. In this upper story she had evi- 
dently succeeded in raising her second brood in safety. 
In the centre of this nest, I found these four eggs thus 
singularly incarcerated. 
There is also another circumstance to which I would 
direct your attention. There are found two kinds of 
parasite eggs so different in marking, as to warrant us in 
considering them the product of different species, did 
we know any other than the cow-troopial to which to 
attribute one of them. One of these eggs is “ thickly 
sprinkled over with grains of pale brown on a dirty white 
ground.” Its thickness is nearly the same throughout. 
This is the egg of the cow black-bird. The other egg is 
considerably larger in size, one end is evidently much 
more pointed than the other, its ground is pure white and 
the spots are much more sparing and are of a much deeper 
tint of brown, nearly approaching to black. To what bird 
does this egg belong ? If to the cow-troopial, in what 
manner shall we explain this unusual difference ? If not, 
to what bird shall we attribute it ? Nuttall, in his account 
of the ambiguous sparrow, which he supposes a new 
species, asks, “ may not this be the offspring of the white 
and more sparingly spotted egg, deposited occasionally in 
the nests of the cow-bird’s nurses ?” If so, why is not 
this rare bird proportionally common with its egg ? 
One word, before concluding, on our cuckoos. To 
show how little these birds deserve the obloquy with 
which they are too often inconsiderately regarded, 1 will 
relate a trivial, but not uninteresting circumstance, which 
fell under my own observation. A nest of the black- 
billed cuckoo, containing three young, was found in Cam- 
bridge in the summer of 1835, and the female, brutally 
shot in the nest by a boy. The young, so far from per- 
the Coiv Black-Bird. 
433 
I*. 
ishing from hunger, were carefully and affectionately 
nursed by the surviving male. Such things are of com- 
mon occurrence among birds in general, but it is what 
would hardly have been expected from the hated and 
much injured cuckoo. 
Among the foster parents of the cow-troopial, Wilson 
enumerates the blue-bird, the chipping-sparrow, the 
golden-crowned thrush, the red-eyed fly-catcher, the 
goldfinch, the Maryland yellow-throat, the white-eyed 
fly-catcher, and the blue-grey flycatcher. To these 
Audubon adds the summer yellow-bird. Nuttall adds 
the indigo-bird, the song-sparrow, and Wilson’s thrush. 
Ord mentions the wood-thrush. To these may be added 
the small pewee in the Society’s collection, the purple- 
finch in that of Mr. S. Cabot Jr., and the bay-winged finch 
in my own. 
1 must crave the indulgence of the Society for tres- 
passing upon so much of their time. The importance of 
having every new fact that is advanced in science duly 
considered, must be my excuse. If I have hesitated 
from insufficient grounds, to dismiss old positions and 
adopt the new ones of Mr. Ord, I trust I have given the 
facts he brings forward, all the weight they deserve. If 
I have felt called upon to notice and animadvert upon a 
spirit of hostility towards co-laborers in the cause of 
science, which but too clearly shows itself in his paper, 
I trust I have done no more than every friend of fair and 
honest criticism will be willing to do in similar cases, no 
matter who be the offender. 
Since making the above communication, I have been 
able to investigate with a little more fulness, the sub- 
VOL. I. PART IV. 56 
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