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 Cuculidse 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 bill 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 great 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 

 black volcanic sand which is both clamp and warm, either by the sea- 

 shore or in the vicinity of warm springs in the interior. In any case 



