4 oo MY LIFE 



such very diverse groups of birds interested me greatly, and 

 I endeavoured to explain them in accordance with the laws 

 of natural selection. In the paper on Pigeons (published 

 in The Ibis of October, 1865) I suggest that the excessive 

 development of both these groups in the Moluccas and 

 the Papuan islands has been due primarily to the total ab- 

 sence of arboreal, carnivorous, or egg-destroying mammals, 

 especially of the whole monkey tribe, which in all other 

 tropical forest regions are exceedingly abundant, and are 

 very destructive to eggs and young birds. I also point out 

 that there are here comparatively few other groups of fruit- 

 eating birds like the extensive families of chatterers, tanagers 

 and toucans of America, or the barbets, bulbuls, finches, 

 starlings, and many other groups of India and Africa, while 

 in all those countries monkeys, squirrels, and other arboreal 

 mammals consume enormous quantities of fruits. It is clear, 

 therefore, that in the Australian region, especially in the 

 forest-clad portions of it, both parrots and pigeons have 

 fewer enemies and fewer competitors for food than in other 

 tropical regions, the result being that they have had freer 

 scope for development in various directions leading to the 

 production of forms and styles of colouring unknown else- 

 where. It is also very suggestive that the only other country 

 in which black pigeons and black parrots are found is Mada- 

 gascar, an island where also there are neither monkeys nor 

 squirrels, and where arboreal carnivora or fruit-eating birds 

 are very scarce. The satisfactory solution of these curious 

 facts of distribution gave me very great pleasure, and I am 

 not aware that the conclusions I arrived at have been seriously 

 objected to. 



Before I had written these two papers I had begun the 

 study of my collections of butterflies, and in March, 1864, 

 I read before the Linnaean Society a rather elaborate paper 

 on " The Malayan Papilionidse, as illustrating the Theory of 

 Natural Selection." This was published in the Society's 

 Transactions, vol. xxv., and was illustrated by fine coloured 

 plates drawn by Professor Westwood. I reprinted the intro- 



