VOL. XV. J NOTES. !.59 



on six separate occasions. This film was shewn to the 

 British Ornithologists' Clnb and the Zoological Society in 

 November, and illustrated with remarkable clearness the 

 •Cuckoo's glide down from a tree, its actions about the nest, 

 and even the taking of one of the fosterer's eggs in its bill, 

 the last incident being also shown in a slide from a photograph 

 by Miss E. L. Turner. 



The knowledge of when and where the Cuckoo will lay 

 has made it possible, not. only to photograph the bird, but 

 for a number of observers (among them the present 

 writer) to watch it from a " hide " placed close to the 

 chosen nest and perhaps one ol the mcst interesting of 

 Mr. Chance's discoveries has been in connection with 

 the actual egg-laying. After sitting motionless in a crouch- 

 ing attitude for a period varying from one to three 

 hours on a bough of a tree from 50 to 150 yards from the 

 Meadow-Pipit's nest, the Cuckoo glides down to the ground. 

 She then often returns to the tree and glides down again, 

 sometimes several times, but eventually goes to the nest, 

 and having taken out with her bill one of the eggs of the 

 fosterer, sits on the nest and lays her own egg in it. The 

 actual time she is sitting on the nest is remarkably short — 

 from five to eight seconds — and this is no doubt made possible 

 by the egg being ready for extrusion when she leaves the 

 tree. Were this not so, and had the Cuckoo to sit on the 

 nest for an hour or so, the fosterer would doubtless desert. 

 At the same time, Mr. Chance discovered by experiment 

 that the Cuckoo could retain its egg for several hours even 

 after it had made its glide, should the necessity arise. 



That the Cuckoo actually lays in the nest is a verj' interest- 

 ing fact, but Mr. Chance makes it clear that this statement 

 refers only to those birds he has watched. As eggs have 

 oiten been found in nests in which it would be impossible 

 for a Cuckoo to sit, certain individuals must deposit their 

 eggs with the bill. 



We congratulate Mr. Chance on the film, which has a 

 definite value scientifically as well as educationally, and we 

 hope that having discovered so much that was previously 

 unknown he will be encouraged to continue his observations 

 on the Cuckoo's habits, which present many points that 

 are still obscure. — H. F. W. 



The Relation of Soxg to Nesting in Birds. — Mr. 

 J. P. Burkitt contributes a further valuable article on 

 this subject to The Irish Naturalist for October, 192 1. During 

 the past spring and summer he made close observations on 



