152 STUDIES IN LIFE AND SENSE 



point of time or geological sequence, the earliest, quadrupeds. What- 

 ever higher quadrupeds such as the sheep, oxen, horses, &c. the 

 colonisation of Australia has been the means of introducing into 

 that region, it must be borne in mind that all the native mammals 

 of Australia are of the lower grades, and are, with the exception of 

 the American opossums (which do not occur in Australia), absolutely 

 limited to that region. Even the world-wide rodents, represented here 

 by a few rats and mice, are probably of relatively late introduction. 



In ' respect of its birds, whilst Australia possesses species of the 

 familiar thrushes, warblers, shrikes, crows, &c., of the other regions, 

 it yet exhibits certain peculiar forms of bird-life. The bird-absentees 

 are of themselves typical, for Australia has no representatives of the 

 vultures, pheasants, woodpeckers, barbets, and other birds which are 

 so characteristic of even the Oriental territory. But it has, neverthe- 

 less, a rich ornithology of its own, in its birds of paradise, its most 

 typical honeysuckers, its lyre-birds, its scrub-birds, its parroquets, 

 its cockatoos, its mound-birds, and its cassowaries. These are 

 typically Australian forms; and there are bird-families sparingly 

 found in other parts of the world such as the swallow-shrikes and 

 flower-peckers but which are well represented in Australia. Lastly, 

 there are families of birds such as the kingfishers, pigeons, weaver- 

 finches well represented in other provinces, and which are, as a 

 rule, better represented in Australia than in other provinces. 



The reptiles of Australia do not present any special features for 

 remark. Snakes and lizards are plentiful ; and the Australian 

 amphibians number frogs and toads, but no newts, in their Cranks. 

 Thus the Australian region, to sum up, possesses representatives of 

 eighteen families of quadrupeds, eight of these families being 

 absolutely confined to this region. It has seventy-one families of 

 birds, sixteen being peculiar ; it possesses four peculiar families out 

 of thirty-one of reptiles ; and it has only one family of amphibians, 

 out of a total of eleven, confined within its limits. 



Passing now to the Western Hemisphere, we find the New World 

 divided into the Nearctic and Neotropical regions (fig. 13). The former 

 includes North America in its arctic and temperate regions, and is 

 bounded on the south by a line running between Cape Lucas on the 

 west, and the Rio Grande del Norte on the east ; the boundary line 

 dipping southwards from this point in a tongue which extends well- 

 nigh to the Isthmus of Tehuantepec. Between the life of the 

 Nearctic and Palsearctic regions there is a striking resemblance. 

 In North American forests, the wolves, lynxes, foxes, bears, elks, 

 deer, beavers, hares, squirrels, pikas, and marmots of Europe are 

 represented often by similar species ; and the bison of Western 

 Europe represents the buffalo of the Nearctic prairies. But North 

 America has its own peculiar quadrupeds likewise. For instance, 



