220 Major E, F. Meiklejolin on the [Ibis, 



9. *Most female Cuckoos return to the same locality as 

 tliat in which they were themselves reared, aad as it may 

 be assumed that their ancestors selected nests whose eggs 

 resembled their owti, and that egg-coloration is more or 

 less hereditary, they find suitable nests in such localities. 

 HencCj where several foster-parents are available in one 

 locality, Cuckoos laying eggs of different types will collect, 

 and there is more likely to be a shortage of suitable nests 

 and consequently a lower percentage of resemblance. 



10. "^Tiie Hedge-Sparrow, which is singularly ready to 

 adopt eggs of any colour, is the favourite "makeshift'' 

 foster-parent. 



11. *The number of eggs laid yearly is probably nine to 

 twelve. 



12. ^Laying appears to take place at irregular intervals. 



13. *The date of the laying period varies in different 

 localities and corresponds with that of the species selected 

 as foster-parents. 



14. ^Most Cuckoos lay in the same rather restricted 

 locality. 



15. Each female lays eggs of the same type all her life. 



16. *The eggs are probably laid on the ground amongst 

 vegetation or in the forks of trees, and at times may be 

 left there Avith a second or even third egg until suitable 

 nests are found. 



17. Only one egg is placed in any nest, and if two or 

 more are found in the same nest they belong to different 

 females. 



18. When placing its c^^^ in a nest the Cuckoo usually 

 removes one or more of those of the foster-parent. Occa- 

 sionally this is done the day before, and at times other eggs 

 are removed subsequently. In the case of the Cow-birds, 

 the eggs of the foster-parents are either ejected or have a 

 minute puncture made in them, either by the beak or sharp 

 claws, so as to prevent their hatching. 



