18 BIRDS' NESTS 



ture than is generally supposed. I have repeatedly 

 remarked during my birds'-nesting wanderings not 

 only over many parts of the British Islands, but in 

 foreign lands, that the nests of some of the commoner 

 species present a very marked diversity. For instance, 

 the ChafBnch, generally speaking, I have found builds 

 a much less finished nest in Devonshire than in other 

 parts of England, whilst on the other hand the finest 

 nests of the Long-tailed Titmouse I have ever seen were 

 from that county. I was also much struck with the 

 local differences of some of the birds' nests I found 

 in Algeria, belonging to species that also breed in our 

 islands. Doubtless other observers have remarked 

 very similar facts. 



Having thus discarded the theory of instinct or 

 inherited habit, the reader may justly ask what we 

 would offer as a substitute for it ? We may here 

 repeat in substance the matter most closely bearing 

 upon this subject which is contained in a paper written 

 by us and read before a scientific society in Yorkshire 

 some years ago. Mr Wallace's theory that birds do 

 not make their nests instinctively, but by imitating the 

 nests in which they were reared — that if they never 

 saw or were not brought up in a nest peculiar to their 

 species they would be unable to construct one for 

 themselves similar in position, form, and materials is, 

 after the absolute confirmation supplied by the instance 

 of the New Zealand Chaffinches just given, probably 

 the true solution of this interesting problem. The 



