SPREADING OF BIRDS. 73 



19. Of the Land Birds, the Vulture (Vultur], and 

 Falcon (Falco\ which are of nearly the same species, 

 extend over both Hemispheres, as far as the snow- 

 line, and sometimes even farther. Vultures, however, 

 are more numerous in warm countries, although some 

 are found beyond the snow-line. Falcons, on the 

 contrary, are more abundant in the Temperate and 

 Frigid Zones, where they likewise reach beyond the 

 snow-line. Germany numbers among its Birds three 

 Vultures: viz. the Common (Vultur cinereus), the 

 Crested (V. cristatus}, and the Angola Vulture (V. 

 leucocephalus) ; and thirty-seven Falcons, of which 

 nine are Eagles. 



20. The Owl (Strix) is spread over all the habi- 

 table parts of the globe j but none of any of its 

 species are ever naturalized in the vicinity of the 

 snow- line. The regions of Greenland and New- 

 foundland are their natural limits. Germany has 

 fourteen species of this Genus. 



21. The Butcher-Bird (Lanius) inhabits more 

 generally the Warm and Temperate Zones, and 

 never extends, as far as we know, to the Polar Circle 

 on the Northern Hemisphere. Some species of them 

 are seen in the Southern as well as the Northern 

 Hemisphere ; and the L. Melanocephalus, in par- 



D 



