as intricate as that of the red-shafted and 

 yellow-shafted flickers of our continent. 

 The carrion-crow is entirely black; the 

 hooded-crow is gray, with the head, throat, 

 wing, and tail black. The former inhabits 

 in Europe the southern parts, while the 

 hooded-crow is northern and eastern ; but 

 the areas of both overlap, and in those dis- 

 tricts innumerable intermediate specimens 

 occur. Hybridization easily accounts for 

 these, inasmuch as the interbreeding of typi- 

 cal birds of both species is an established 

 fact. But that was not the greatest diffi- 

 culty which presented itself in the apparent- 

 ly western carrion-crow coming to light again 

 in eastern Siberia, to the east of the hooded 

 species. Seebohm has attempted to show 

 that the true explanation is that the black 

 one is originally an eastern species, which 

 has invaded southern Europe, establishing 

 a western colony there after having crossed the area inhabited by its gray cousin. To 

 me the problem seems even easier ; for I think it possible to separate the east Asiatic 

 birds, at least subspecifically, from the European form. 



FlG. 260. Urocissa trytltror/tynchus, red-billed jay. 



