Ivii 



facts presented by the apterous or winged condition of the 

 species. 



This striking peculiarity consists, either in species being 

 apterous in Madeira which are winged elsewhere, or in genera 

 which are usually winged consisting of only apterous species in 

 Madeira, or lastl}'^ in the presence of endemic apterous genera, 

 some of which have winged allies while others belong to groups 

 which are wliollj'^ apterous. Such phenomena undoubtedly show 

 that there is something in Madeira which tends to abort wings ; 

 and Mr. Wollaston was himself the first to suggest that it was 

 connected with exposure to a stormy atmosphere. His further 

 observation, that many of the winged species had wings more 

 developed than usual, enabled Mr. Darwin to hit upon that 

 beautiful explanation of the facts which commends itself to all 

 who believe in the theory of Natural Selection ; while Mr. Wol- 

 laston himself admits it as fully accounting, teleologically, for the 

 phenomena. That explanation briefly is, that the act of fl3"ing 

 exposes insects to be blown out to sea and destroyed ; those which 

 flew least therefore lived longest, and by this process the race 

 became apterous. With species to whom flight was a necessity, 

 on the other hand, the strongest winged lived longest, and thus 

 their wings became more and more developed in each succeeding 

 generation. 



Now this view of the case enables us at once to explain some 

 of the most striking gaps in the Madeiran coleopterous fauna. 

 The Cicindelidae, for instance, are entirely absent ; and almost all 

 the European species are winged insects of somewhat feeble 

 flight, yet to whom flight is necessary. We can readily understand 

 that such insects would be easily exterminated if they arrived 

 singly or in small numbers ; though it is not so easy to under- 

 stand why, in a forest-clad island, some of the sylvan species 

 should not have found a home had the land ever been connected 

 with a continent where they abound. Their total absence is, 

 therefore, decidedly unfavourable to the theory of a land-con- 

 nection with Europe. To the Melolonthidse and Cetoniidae, as 

 well as the Eumolpidae and Galerucidse, which are all wanting, 

 the same argument will apply; and also to the Elateridae and 

 Buprestidffi, which are represented each by one minute species. 

 But if Madeira is the remains of a continent once continuous 

 with the south of Europe and deriving its fauna from such con- 



