226 HABIT AND INTELLIGENCE. [chap. 



bited by a bird, less sluggish than the dodo, but also 

 "^f . unable to fly, called the solitaire: these two species are 

 stated to be allied to the pigeons.^ But the most remark- 

 able group in the world of such birds is that which is now 

 becoming extinct in New Zealand. These are not allied 

 to the pigeon, but are of the same order with the ostrich. 

 The _ The extinct diiiornis, the largest of all birds, was of this 

 family, which is now represented by the comparatively 

 The small apteryx. As indicated in the name of the apteryx, 



ap eiyx. ^j^ggg ]3ij.(jg not only are unable to fly, but are without 

 external wings. I believe the origin of these remarkable 

 species is to be accounted for in the same way as that of 

 the species of bats mentioned in the last paragraph. It is 

 to be observed that the islands to which those birds belong 

 contain no native mammalia whatever, except, I suppose, 

 Origin of bats. The only assignable origin of those species of birds 

 such races. ^^ ^-^^^ they are descended from flying birds, which were 

 blown across the ocean long ages ago, and, finding the 

 country uninhabited, became the ancestors of birds which, 

 having plenty to eat and few enemies, in successive gene- 

 rations grew to an enormous size, and lost the power of 

 flight. As the islands are without native mammalia, 

 they could have few if any enemies on the ground ; and 

 if there were birds of prey, these could perhaps be best 

 eluded by keeping on the ground among the dense 

 vegetation of those islands, and not endeavouring to use 

 the power of flight. 

 Cuvier's We may conclude, that although the principle of the 



wVn not^ adaptation of every organic species to its mode of life, and 

 explain the ^o the external conditions of its life, is generally true, and 

 distribu- of great importance, yet it utterly fails to account for the 

 **°^' facts of the geographical and geological distribution of 



These facts species ; while the facts of distribution give some support 

 the fteory ^^ ^^^^ theory of the origin of species by descent with 

 of descent modification. Especially is this true of the facts, that 

 fication. geology shows the same area to have been usually inha- 

 bited during two successive geological periods by similar 

 though different species ; and that geographical zoology 



1 See "The Dodo and its Kindred," by H. E. Strickland, F.G.S. 



