294 THE ARU ISLANDS. [chav. xxxiii. 



Java, where a considerable number of the continental 

 species are represented by allied forms, the separation was 

 more remote. 



From these examples we may see how important a 

 supplement to geological evidence is the study of the 

 geographical distribution of animals and plants, in deter- 

 mining the former condition of the earth's surface; and 

 how impossible it is to understand the former without 

 taking the latter into account. The productions of the 

 Aru Islands offer the strongest evidence that at no very 

 distant epoch they formed a part of New Guinea ; and 

 the peculiar physical features which I have described, 

 indicate that they must have stood at very nearly the 

 same level then as they do now, having been separated 

 by the subsidence of the great plain which formerly con- 

 nected them with it. 



Persons who have formed the usual ideas of the vegetation 

 of the tropics — who picture to themselves the abundance 

 and brilliancy of the flowers, and the magnificent appear- 

 ance of hundreds of forest trees covered with masses of 

 coloured blossoms, will be surprised to hear, that though 

 vegetation in Aru is higlily luxuriant and varied, and 

 would afford abundance of fine and curious plants to 

 adorn our hothouses, yet bright and showy flowers are, 

 as a general rule, altogether absent, or so very scarce 



