CROW 



589 



" Both these [birds] inhabit Europe, but their range and the time 

 of their appearance are very different. Without going into minute 

 details, it will suffice to say that the former is, speaking generally, a 

 summer-visitant to the south-western part of this quarter of the globe, 

 and that the latter occupies the north-eastern portion — an irregular 

 line drawn diagonall}' from about the Firth of Clyde to the head of 

 the Adriatic about marking their respective distribution, l^ut both 

 are essentially migrants, and hence it follows that when the black 

 crow, as summer comes to an end, retires southward, the grey crow 

 moves downward, and in man}' districts replaces it during the winter. 

 Further than this, it has now been incontestably proved that along 



or near the boundary where these two birds march, the}- not in- 

 frequently interbreed, and it is believed that the hybrids, which some- 

 times wholly resemble one or other of the parents, and at other times 

 assume an intermediate plumage, pair indiscriminately among them- 

 selves, or with the pure stock. Hence it has seemed to some ornitholo- 

 gists who have studied the subject, that these two birds, so long 

 unhesitatingly regarded as distinct species, are only local races of one 

 and the same dimorphic species." 



Over a large part of Great Britain, especially the eastern counties 

 of England and many districts of Scotland, the crow, owing to 

 incessant persecution by gamekeepers, is now a rare, or indeed 

 almost unknown bird, as is likewise the case in Ireland. Although 

 generally supposed to differ from the rook by associating in pairs. 



