274 



ISLAND LIFE. 



[fart. it. 



The land-shells are not abundant — about tAventy in all, 

 most of them peculiar species, but not otherwise remarkable. 

 The observation of Captain Collnet, quoted by Mr. Darwin in 

 his Journal, that drift-wood, bamboos, canes, and the nuts of a 

 palm, are often washed on the south-eastern shores of the 

 islands, furnishes an excellent clue to the manner in which many 

 of the insects and land-shells may have reached the Galapagos. 

 Whirlwinds also have been known to carry quantities of leaves 

 and other vegetable debris to great heights in the air, and 

 these might be then carried away by strong upper currents and 

 dropped at great distances, and with them small insects and 

 mollusca, or their eggs. We must also remember that volcanic 

 islands are subject to subsidence as well as elevation ; and it is 

 quite possible that during the long period the Galapagos have 

 existed some islands may have intervened between them and 

 the coast, and have served as stepping-stones by which the 

 passage to them of various organisms would be greatly facilitated. 

 Sunken banks, the relics of such islands, are known to exist in 

 many parts of the ocean, and countless others, no doubt, remain 

 undiscovered. 



The Keeling Islands as illustrating the manner in which Oceanic 

 Islands are Peopled. — That such causes as have been here ad- 

 duced are those by which oceanic islands have been peopled, is 

 further shown by the condition of equally remote islands which 



Acilius incisus. Heteromera. 

 Copelutus galai3agoeiisis. JStomiun helopoides. 



Palpicornes. 

 Tropisternus lateralis. 

 Philhydrus sp. 



StAPHYLINID/E. 



Creophilus villosus. 



Necrophaga. 

 x\cribis serrativeiitris. 

 Phalacrus darwinii. 

 Dermestes vulpiniis. 



CURCULIONID.E. 



Otiorhynchus cuneiformis 

 Anclionus galapng-oensis. 



Longicor.n'ia. 

 EbiiriM aniabilis. 



,, Isevigaturn. 

 Ammophorus obscurus. 

 „ cooksoni. 

 „ bifoveatus. 

 Pedonoeces galapagoensis. 



„ pubescen?. 

 Phaleria raanicata. 



ANTHROIDiE. 



Ormiscus variegatus, 

 Phytophaga. 

 Diabrotica limbata. 

 Docema galapagoensis. 

 Loiigitarsus limatufi!. 



SECURIPALPEy. 



Scyiiiniis galapngoc'ai.sip. 



