ARGENTINE COW-BIRD 87 
tageous. Of the Coccyzus melanocoryphus, the only 
one of our three Coccyzi whose nesting habits I am 
acquainted with, I can say that it never begins to 
incubate till the full complement of eggs are laid— 
that its young are hatched simultaneously. But if 
it is sought to trace the origin of the European 
Cuckoo’s instinct in the nesting-habits of American 
Coccyzi, it might be attributed not to the aberrant 
habit of perhaps a single species, but to another and 
more disadvantageous habit common to the entire 
genus, viz., their habit of building exceedingly frail 
platform-nests from which the eggs and young very 
frequently fall. By occasionally dropping an egg in 
the deep, secure nest of some other bird, an advantage 
would be possessed by the birds hatched in it, and 
in them the habit would perhaps become hereditary. 
Be this as it may (and the one guess is perhaps as 
wide of the truth as the other) there are many genera 
intermediate between Cuculus and Molothrus in which 
no trace of a parasitic habit appears; they belong to 
different orders, and it seems more probable that 
the analogous instincts originated independently in 
the two genera. As regards the origin of the instinct 
in Molothrus, it will perhaps seem premature to 
found speculations on the few facts here recorded, 
and before we are acquainted with the habits of 
other members of the genus. That a species should 
totally lose so universal an instinct as the maternal 
one, and yet avail itself of that affection in other 
species to propagate itself, seems a great mystery. 
Nevertheless I cannot refrain from all conjecture 
