chap. xiii. J • THE AUSTRALIAN REGION. 421 



the former are almost always the largest. As examples may be 

 mentioned, Ornithoptera priamus and 0. helena of the Moluccas, 

 both larger than the varieties (or species) of Papua ; Papilio 

 ulysses and deiplwbus of Amboyna, usually larger than their 

 allies in New Guinea ; Hestia idea, the largest species of the 

 genus ; Diadema pandarus and Charaxes euryalus, both larger 

 than any other species of the same genera in the whole archi- 

 pelago. It is to be noted also, that in the Moluccas, the very 

 largest specimens or races seem always to come from the small 

 island of Amboyna ; even those of Ceram, the much larger island 

 to which it is a satellite, being almost always of less dimensions. 

 Among Coleoptera, the Moluccas produce Euchirus longimanus, 

 one of the largest and most remarkable of the Lamellicornes ; 

 Sphingnotus dunningi, the largest of the Austro-Malayan Tme- 

 sisterninas ; a Sphemira, the largest and handsomest of an exten- 

 sive genus ; an unusually large Schizorhina (Cetoniidse) ; and 

 some of the most remarkable and longest-horned Anthotribidoe. 

 Even in birds the same law may be seen at work, — in the Tany- 

 siptera nais of Ceram, which has a larger tail than any other in 

 the genus ; in Centropus goliath of Gilolo, being the largest and 

 longest-tailed species ; in Hydrornis maximus of Gilolo, the 

 largest and perhaps the most elegantly and conspicuously 

 coloured of all the Pittidse ; in Platycercus amboinensis, being 

 pre-eminent in its ample blue tail ; in the two Moluccan lories 

 and Eos rubra, being more conspicuously red than the allied New 

 Guinea species ; and in Mcgapodius wallacei of Bouru, being the 

 only species of the genus conspicuously marked and banded. 



All these examples, of larger size, of longer tails or other 

 appendages, and of more conspicuous colouring, are probably 

 indications of a less severe struggle for existence in these islands 

 than in the larger tract of New Guinea, with a more abundant 

 and more varied fauna ; and this may apply even to the smaller 

 islands, as compared with the larger in the immediate vicinity. 

 The limited number of forms in the small islands compared 

 with a similar area in the parent land, implies, perhaps, less 

 competition and less danger ; and thus allows, where all other 

 conditions are favourable, an unchecked and continuous de- 



