120 THE STORY OF THE BIRDS 



The Pediophili, or Sand-Grouse, are a small 

 order, entirely restricted to certain portions of 

 the Eastern Hemisphere. It is most abundantly 

 represented in the arid desert districts of the 

 Ethiopian Region, and in similar localities in 

 the central portions of the Palaearctic Region. 

 Sand-Grouse occur sparingly in the Oriental 

 Region, and still more so in the extreme south- 

 west of the Palaearctic Region. The next order, 

 the Columbiformes, or Pigeons, may be said to 

 be almost cosmopolitan in their distribution, 

 although they are very unequally divided amongst 

 the various zoological regions. In the first place 

 they are by far the least abundant in cold or 

 northern latitudes, so that the Palaearctic and 

 Nearctic Regions are the poorest in species. The 

 Ethiopian Region also is not very abundantly 

 represented ; the Neotropical Region is much 

 richer, as is also the Oriental Region ; whilst the 

 Australian Region is remarkable for the abund- 

 ance and variety of this order of birds. This 

 latter region is undoubtedly eminently favour- 

 able to the development of the Columbiformes. 

 It abounds in islands, and thus affords those 

 facilities for isolation so favourable to the estab- 

 lishment of new species, and is singularly free 

 from the many predaceous animals — especially 



