96 THE POPULAR SCIENCE MONTHLY 
study of their habits gives no support to the idea advanced by Darwin, 
in his “ Origin of Species,” that they are passing along the same road 
to parasitism already traversed by their European relative. I do not 
know whether the American cuckoos ever built a better nest or not, but 
it is certain that the present structure is adequate to their needs, and 
affords no evidence of a waning instinct of nidification. (4) The final 
stage of the parasitic instinct among the Cuculide is presented by their 
famous European representative, Cuculus canorus, in which the in- 
stincts of both young and adult have become so specialized that to 
describe them at all adequately would require many pages. One hun- 
dred and nineteen different species of birds have been the prey of this 
parasite, the eggs of which have become reduced in size and highly 
variable in form and color. The commonest dupes are birds of small 
size, like the hedge sparrow and titlark; but one egg is laid in the same 
nest by the same bird, and this is often similar in size and coloring to 
those of the prospective nurse. The egg is deposited stealthily in the 
stolen nest, and in the absence of the owner, either just before or just 
after the proper eggs have appeared, or it is first dropped on the ground 
and conveyed to the nest in pill or gullet, by which the range of acces- 
sible nests is greatly increased. These and other remarkable practises 
of this bird have been fully described in a paper on the “ Life and 
Instincts of the Cuckoo,” shortly to appear. 
All travelers who have studied the ostriches of South America 
and Africa in the field speak of the ereat numbers of their eggs which 
are annually wasted both in and out of season by dropping them over 
the plains or around their nests. If this is a secondary character, it 
must have come from a disturbance of the normal cycle, quite similar 
to what we have found in cuckoos and starlings. In this case adjust- 
ment seems to have been effected in quite a different manner, for we 
find the male taking upon himself almost the whole duty of incubation 
and care of the young. Even the wasted eggs, at least in the neighbor- 
hood of the nest, serve a secondary use as food, for the young soon break 
them open and devour them. 
We can not discuss with much profit the remarkable breeding habits 
of the megapodes of Australia and the East Indies, referred to earlier 
in this paper, until naturalists have made more detailed studies upon 
the various species. The notes which follow are purely tentative, and 
are offered by way of suggestion. The true megapodes build huge 
mounds of earth and leaves, which serve as incubators for their eggs, 
and the young, which may or may not be subsequently tended by their 
parents, are in most cases able to run or fly from birth, or when they 
emerge from their mound. ‘The moleos or “ maleos” deposit theirs in 
plack volcanic sand which is both damp and warm, either by the sea- 
shore or in the vicinity of warm springs in the interior. In any case 
