334 
Recently published Ornithological Works. [Ibis, 
he distinguishes fourteen races spread over the Palsearctic 
Region. He divides these fourteen races into three groups, 
and he believes that when individuals belonging to different 
groups extend their range towards one another's territory 
hybridization occurs, and that such hybrids follow' the 
Mendelian laws. Also that in some cases pure-blooded 
individuals revert to the more primitive types from which 
they are sprung, and that a clear distinction should be 
drawn between them and the hybrids. By means of these 
hypotheses he endeavours to account for the many varying 
forms of Long-tailed Tits met with in the Palsearctic 
Region. 
With regard to the Bullfinches the problem appears more 
simple, but here, too, the explanation is hybridization 
between two comparatively distinct forms. The larger, 
Pyrrhula p. pyrrhula , of the east and north, and the 
smaller, Pyrrhula p. minor and P. p. pileata , of the west, 
have spread out since the Ice Age and met in southern 
Germany, where a mixed or hybrid form, known as P. p. 
germanica , h: s established itself. Such in brief appears 
to be the views of our author on these difficult and com¬ 
plicated questions. 
Bird-Lore. 
[Bird-Lore: A bi-monthly Magazine devoted to the Study and 
Protection of Birds. Yols. xxi. & xxii. for 1919 & 1920.] 
The two volumes of ‘Bird-Lore' under notice contain a 
number of articles of considerable interest, especially to the 
bird-lover in America, to whom they are specially addressed. 
We must confine ourselves to mentioning some of those of 
more general interest. The Editor, Mr. Prank Chapman, 
during the last part of the war was a travelling com¬ 
missioner for the American Red Cross and, in that capacity, 
made a rapid journey through South America, visiting 
Peru, Chile, and the Argentine. His impressions on the 
bird-life of those countries will be found in a series of vivid 
articles illustrated with photographs and drawings. Perhaps 
