78 A HISTORY OF BIRDS 



North Africa and the easternmost extremity of South America. 

 Into the evidence for this, however, there is no need to enter 

 here, as this evidence is supplied by the facts of mammalian 

 distribution, and will be dealt with in the volume dealing with 

 this group. 



The peculiarities of avian distribution with which we are 

 here concerned can be explained without the aid of a Southern 

 Antarctic Continent. 



There are some significant facts, furnished by existing 

 species, which support this contention, and these are provided 

 by some of our commonest British birds. The Nuthatches, for 

 example, represented in Great Britain by the Common Nut- 

 hatch {Sitta cassia), ranges throughout Europe, North Asia, 

 North America, India, China, Indo-Malaya and Australia. 

 The Gold-crests {Regulidce), represented by two species in 

 Great Britain, range throughout Europe, North Asia and North 

 and Central America. The Wax-wings in Europe and Asia — 

 essentially northern types — pass into North America and then 

 southwards into Central America. The Dippers {Cinclidce) 

 range throughout Europe and Asia, and crossing into North 

 America — -via North Asia^ — -pass into South America. 



Now it is significant to note that there are certain Families 

 which occur in Southern Europe which range into Africa and 

 India, pass by the Indo-Malay Peninsula into Australia, but 

 which do not occur in America, as for example, the Bee-eaters 

 {Meropidce), and others, as the Bulbuls, Hornbills and Trogons, 

 which are met with only in Africa, India and the Indo-Malay 

 Peninsula. These possibly originated in southern latitudes, 

 and hence did not find their way into America, as did those 

 which originated in Northern Europe. 



But there are some Families, such as the Barbets {Capitones) 

 and Jacanas {Parrce) which are found in Africa, India, the 

 Indo-Malay Peninsula and Australia, and South America. The 

 occurrence of these birds in South America may be due to the 

 land bridge between Africa and South America referred to 

 already. 



Intp the details of the distribution of these Families it is not 

 the province of this chapter to enter, nor into the several species 

 and sub-species, or geographical races, by which these Families 

 are represented : our aim being to account for the discontinuous 



