270 FroceecUngs of the Fioyrd Irish Academi/. 



writers, he contended, had really grappled vriXh the facts as a Avhole. 

 In 1900, he republislied his address, stating, in afoot-note (A p, 250), 

 that, it may serve as a reply, not only to the arguments advanced by 

 the late Andre-sv ^ilurray, hut also to similar vieTVs still occasionally 

 put for^rard. 



As many writers have expressed themselves against Dr. Wallace's 

 views since the first publication cihii address, I venture again to 

 give the salient points advanced by him, and to bring forward a few 

 arguments which appear to me to favour the older doctrines of ilurray 

 and others. I have also paid special attention to the fauna of the 

 Atlantic Islands as a whole, with the view to reinvestigating the 

 " Atlantis problem." 



Dr. "Wallace's address deals only with the beetles of Madeira, one of 

 the Atlantic islands ; but h.e maintains that the opinion he enunciates, 

 and which is founded on a study of these insects, explains the origin 

 of the !Madeiran and of other insular faunas. 



One of the most striking characters of the coleopterous fauna of 

 ^Madeira is the unexampled preponderance of wingless species on the 

 island. Darwin's ingenious explanation of this remarkable pheno- 

 menon is that the act of flying would expose the insects to being 

 blown out to sea, and thus destroyed. Those insects which, flew least 

 would tkerefore remain behind in increasing numbers ; and by a 

 continuous process of natural selection, a race of wingless forms would 

 thus, in the course of ages, become established on the island. 



If Madeira, asks Dr. Wallace, were the remains of a continent, 

 once continuous with the south, of Europe, and deriving its fauna from 

 such, continuity, how are we to explain the absence of extensive 

 genera very abundant in southern Europe, and, from their being 

 wingless, .specially adapted to the peculiarities of Madeira ? Such, he 

 continues, are Carahus, Lamp yr is, Pimelia, Ahis, and many others. 

 The genus Carahm — a prominent member of the large family of 

 mnning-beetles — possesses, according to Dr. Wallace, 80 species in 

 southern Europe and northern Africa, while not a single species has 

 crossed to Madeira. Many other similar facts are set forth by the 

 same author ; and these seem to him quite inconsistent with the 

 theory of the distribution of insects having been effected by a former 

 land- connection with Europe. Their transmission appears to him to 

 have been brought about, not by means of drift-wood or ocean 

 currents, but by a passage through, thie air when assisted by gales and 

 hurricanes. 



jS'ow it is evident that if Madeira had ever been connected bv land 



