400 Natural History 



but of these only 70 belong to the usually abundant tribes of 

 the Avaders and swimmers, indicating that these are very im- 

 perfectly known. As they are also pre-eminently wanderers, 

 and are thus little fitted for illustrating the geographical dis- 

 tribution of life in a limited area, we will here leave them 

 out of consideration and confine our attention only to the 

 195 land-bii'ds. 



When we consider that all Europe, with its varied climate 

 and vegetation, with every mile of its surface explored, and 

 with the immense extent of temperate Asia and Afi-ica, which 

 serve as store-houses, from which it is continually recruited, 

 only supports 257 species of land-birds as residents or regular 

 immigrants, we must look upon the numbers already procured 

 in the small and comparatively unknown islands of the Mo- 

 luccas as indicating a fauna of fully average richness in this 

 department. But when we come to examine the family groups 

 which go to make up this number, we find the most curious 

 deficiencies in some, balanced by equally striking redundancy 

 in others. Thus if we compare the birds of the Moluccas 

 with those of India, as given in Mr. Jerdon's work, we find 

 that the three groups of the parrots, kingfishers, and pigeons 

 form nearly one-third of the whole land-birds in the former, 

 while they amount to only one-twentieth in the latter country. 

 On the other hand, such wide-spread groups as the thrushes, 

 warblers, and finches, which in India form nearly one-third of 

 all the land-birds, dwindle down in the Moluccas to one-four- 

 teenth. 



The reason of these peculiarities appears to be, that the 

 Moluccan fauna has been almost entirely derived from that 

 of New Guinea, in which country the same deficiency and 

 the same luxuriance is to be observed. Out of the seventy- 

 eight genera in which the Moluccan land-birds may be classed, 

 no less than seventy are characteristic of New Guinea, while 

 only six belong specially to the Indo-Malay islands. But 

 this close resemblance to New Guinea genera does not extend 

 to the species, for no less than 140 out of the 195 land-birds 

 are peculiar to the Moluccan islands, while 32 are found also 

 in New Guinea, and 15 in the Indo-Malay islands. These 

 facts teach us, that though the birds of this group have evi- 

 dently been derived mainly from New Guinea, yet the immi- 



