AVICULTUBAL EXPERIENCES. 255 



lower jaw in the males than in the females. The Doves are very- 

 difficult to sex where colour-characters are wanting, but the males 

 usually, if not always, show a more prominent forehead than the 

 females. 



If there were no truth in these differences, it would be im- 

 possible for the aviculturist, when dealing with species in which 

 the sexes showed no colour differences, to select pairs for breed- 

 ing purposes. If we take the common Java Sparrow (Paclda 

 oryzivord) as an example, I may state that at various times I have 

 picked out pairs repeatedly, both for myself and others, for 

 breeding purposes, and hitherto have never been wrong in my 

 selection ; or, if we take the Crested Cardinal (Paroaria cucullata) 

 — from five specimens which I purchased some years ago, I 

 selected a pair, and placed them together in an aviary. Presently 

 the cock began to sing and show off to the hen, a nest was built, 

 and one or two eggs dropped on the floor, proving conclusively 

 that my pairing had been correct. 



It has been objected that, allowing the sexual differences in 

 the beaks of birds to be reliable when the creatures are alive, so 

 much shrinkage takes place after death, that the character of 

 the beak is modified so as to be untrustworthy for comparison. 

 This, however, is an error based upon supposition rather than 

 experiment. The beak, being the horny sheath of a bony 

 structure, changes its character very little ; indeed, if it did it 

 would hardly form a suitable basis for generic or specific 

 diagnosis. 



Touching the construction of nests by birds, a great deal of 

 poetic nonsense has been written. Most nests are pleasing 

 objects, and some are extremely artistic ; but it is not true that 

 the most elaborate nest is entirely beyond imitation by a skilled 

 workman ; indeed, I am satisfied that a Chinese artist would be 

 able to fashion an excellent copy of the nest of a Long-tailed Tit 

 (that most beautiful of English types) in a tithe of the time 

 occupied by the birds. As for the cup-shaped nest, it is formed 

 in the most rough-and-ready fashion, and its beauty is dependent 

 largely upon the materials used in its construction. If you 

 watch a Finch building in a bush, as I have frequently done in 

 my aviaries, you will be astonished to discover how easily it is 

 managed. The hen bird picks up a long piece of hay or a grass- 



