THE WARBLERS 



Some systematlsts are disposed to class the Crows 

 as the most highly specialized of all known birds ; 

 and if certain peculiarities are considered their right 

 to the distinction seems to be beyond question. 

 Other naturalists have similarly urged the claims 

 of the Thrushes to that honour, but with less satis- 

 factory evidence to support their views. The Crows, 

 as was long ago remarked by the illustrious Mac- 

 gillivray, rank amongst some of the most highly 

 organized birds. This assertion was based not only 

 upon great anatomical, but wide general knowledge, 

 and has been abundantly confirmed by later investi- 

 gations. This exalted position of the Crow family 

 {CoTvidcB) is largely due to the very interesting 

 morphological fact that the young birds resemble 

 the adults in colour, a fact which assuredly indicates 

 higher development than is attained by the majority 

 of other birds — and perhaps all other groups col- 

 lectively — in which the young are more or less char- 

 acterized by a plumage differing in many important 

 respects from that of their parents. Tested by this 



