366 Mr. Alfred R. Wallace on the 



fruit- eating birds, as a whole, are more abundant in South 

 America than in these islands, proves that their comparative 

 scarcity cannot be attributed to a deficiency of appropriate food. 

 It is to be noted, however, that the most striking superabun- 

 dance of Pigeons, as well as of Parrots, is confined to the Austro- 

 Malayan subregion, in which, although the most luxuriant 

 forests everywhere clothe the country, and fruit-bearing trees, 

 especially those of the Fig tribe, are very abundant, yet all the 

 forest-haunting and fruit-eating mammals, such as Monkeys and 

 Squirrels, are totally absent. But Monkeys, besides consuming 

 vast quantities of fruit, are exceedingly destructive to eggs and 

 young birds ; and Pigeons, which build rude, open nests, and 

 whose young are a long time helpless, must be more particularly 

 exposed to their attacks. This is no doubt the reason why, in 

 the dense forests of the Amazon, where Monkeys are most 

 abundant. Pigeons are scarce or almost entirely absent ; and in 

 South America generally, it is to be observed that by far the 

 larger number of the Pigeons inhabit the districts where Mon- 

 keys are almost or quite wanting — the mountains of Chili and 

 of Mexico, the open plains of the Oiinoko and La Plata, and 

 the savannas of Central Brazil. The South American Pigeons 

 are mostly ground-feeding species, and build in low bushes and 

 thickets to which Monkeys rarely descend. In India and Africa, 

 where Monkeys, especially the smaller kinds, are less abundant, 

 true fruit-eating Pigeons occur, feeding and building on lofty 

 trees, and protected to some extent by the green tints of their 

 plumage. They form, however, in these countries but a small 

 portion of the group, whereas more than two-thirds of the 

 Pigeons of the Malay Islands are fruit-eaters of the genera 

 Treron, Ptilonopus, and Carpophaga, which never descend to the 

 ground, and are true denizens of the dense virgin forests. We 

 may also remark that in these regions there are no great families 

 of fruit-eating Passer'es like the Tanagers and Chatterers of 

 tropical America, whose place seems to be in some measure 

 supplied by the Fruit-Pigeons, which, being generally larger birds, 

 consume a vast quantity of fruit. The great development and 

 rapid increase of these, unchecked by the competition of fruit- 

 eating mammals, or by the attacks af arboreal carnivora, would 



