J 35 



A USTRALASIA II. I- f '.V TRA 77:7 >. 



took place. Australia is still in the secondary period of animal and plant development." 

 But a comparison of the Australian animals and plants of the present day with the 

 fossil forms of the secondary period, will show that, though such a statement embodies 

 a truth, it is on the whole one-sided and misleading-. Living Australian forms throw 

 great light on certain fossils found in European and American secondary strata ; but 

 Australia is in no sense still in the secondary period. If we examine the Australian 



fauna as a whole, we 

 shall find that it presents 

 a number of forms which 

 are especially character- 

 ized by their modern 

 \ character. Frogs, which 



are, geologically con- 

 sidered, so far as fossil 

 evidence goes, more mod- 

 ern than marsupials, are 

 remarkable for their de- 

 velopment, and the num- 

 ber of genera and species 

 represented ; we have re- 

 presentatives of most of 

 the families of fresh-water 

 fishes found in other parts 

 of the earth, of most of 

 the groups of modern 

 birds and of reptiles ; and 

 we have even some mam- 

 mals bats, flying-foxes, 

 native rats and mice 



which have nothing ancient about them. Intermingled, however, with these, are a variety 

 of undoubtedly archaic forms the marsupials, the duck-bill and spiny ant-eater, the 

 emus and cassowaries, and that remarkable survival, the L'cratodus. 



There appears to be sufficient evidence that the present faunal (as well as, of course, 

 floral) characteristics of Australia, with this intermixture of ancient with modern forms, 

 were produced somewhat as follows : The body of land which represented in the 

 secondary period what is now Australia, was, towards the close of that epoch, divided 

 into two portions an eastern and a western. These two great subdivisions of Australia 

 were separated from one another for a long period in such a manner that there was 

 comparatively little passage of living forms from the one to the other. The western 

 division remained in a state of isolation from other regions, and the secondary forms 

 which had spread to it from other parts of the earth's surface at an earlier period 

 remained almost its only inhabitants, little disturbed by invasions from without, though 

 undergoing a gradual development, through which were evolved, in course of ages, from 

 the primitive secondary forms most of the peculiar families characterizing the existing 



THE BUTCH 1 



1UKD. 



