254 STUDIES, SCIENTIFIC AND SOCIAL 



wanting in the Goleoptera Atlantidum and in the Goleoptera 

 Hesperidum. 



The most novel and striking facts brought out by Mr. 

 Wollaston's researches in Madeira are, as is well known, — 

 1st. The affinity with the Mediterranean fauna ; — 2nd. 

 The total absence of certain large divisions of Goleoptera 

 abundant in that fauna ; — 3rd. The number of new and 

 peculiar species and of new and anomalous genera ; — and 

 4th. The unexampled preponderance of apterous (wingless) 

 species. If we accept, as all naturalists now do, the 

 theory of slow change of forms by natural causes, we 

 may take the first and third of these facts as proving 

 that the origin of the Madeiran fauna is of very ancient 

 date. Let us see therefore how the second and the fourth 

 set of facts bear upon the mode of its origin, whether 

 by a land- connection with Europe or by transmission 

 across the sea. It will be convenient to take first the 

 facts presented by the wingless 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 lastly in the presence of endemic 

 apterous genera, some of which have winged allies while 

 others belong to groups which are wholly without wings. 

 Such phenomena undoubtedly show that there is some- 

 thing 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. Wollaston himself admits it as fully 

 accounting, teleologically, for the phenomena. That expla- 

 nation briefly is, that the act of flying exposes insects to 

 be blown out to sea and destroyed ; those which flew least 

 therefore lived longest, and by this process the race be- 

 came apterous. With species to whom flight was a neces- 

 sity, on the other hand, the strongest winged lived longest, 



