100 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



It is not possible here to go fully into the fascinating subject of 

 the method of deposition of eggs, but briefly it may be said that 

 it has been fully proved that in manj^ cases cuckoos lay their eggs 

 directly into open nests, an act that has been witnessed by myself, 

 Whitehead, and others in India and proved by Chance (1922) to be 

 the case in England. 



There are, however, any number of eggs deposited by cuckoos in 

 nests into which it is utterly impossible for the cuckoo to gain an 

 entrance. Into many of these the cuckoo projects her egg from the 

 cloaca by pressing herself up against the entrance to the nest and 

 ejecting her egg with sufficient force to propel it the 2 or 3 inches 

 that may be necessary for it to reach the nest (Livesey, 1936; A. E. 

 Jones, 1937). 



On the other hand, there are many nests to which this method 

 also would not apply, such as nests of small birds, more than 2 or 3 

 inches inside holes of various character, in some cases a corner having 

 to be turned before the nest is reached. Into these I believe the 

 cuckoo places her egg with her bill, and there is some evidence to 

 support this which I hope to give in my proposed book on "Cuckoo 

 Problems." 



Young. — Incubation, I think, takes usually 12 or 13 days, rarely 

 only 11 days but occasionally extending to 14. The period the nest- 

 ling remains in the nest is 4 to 6 weeks, but in many cases the nest 

 is far too small to retain the young cuckoo until it is full grown. 

 Thus when the eggs are deposited in the nests of birds such as 

 Cisticola and, to a lesser degree, Suya, the young bird when a quarter 

 grown fills the small egg-shaped nest, sitting in it with its head 

 projecting from the entrance at the top side. Gradually, as the 

 young cuckoo grows, the nest is expanded until it looks like basket- 

 work around it, which finally bursts, depositing him or her on the 

 ground. This generally occurs when the cuckoo has fair feathering 

 and is about half grown or a little later. 



The young Khasia Hills cuckoo ejects the fosterer's eggs or young 

 from the nest in the same way as its English cousin does, possessing 

 the same curious interscapulary pit to assist it in doing so. This 

 structural aid to ejection is found in all such genera as Cuculics, 

 Cacomantis, Penthoceryx, and others that eject their foster brothers 

 and sisters, but not in the young of Clamator, Eitdi/namis, and those 

 cuckoos that do not commit such murders. In the cuckoos that pos- 

 sess it, the pit soon fills in and young cuckoos lose the impulse to 

 eject after a very short time, sometimes within 4 days and almost 

 invariably within a week of being hatched. 



Plumages. — Male: Wliole upper plumage and wing coverts a dark 

 slaty-gray or blackish slate, decidedly darker than the same parts in 



