274 
ISLAND LIFE. 
[part. it. 
The land-shells are not abundant — about twenty 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. 
Copelatus galapagoensis. 
Palpicornes. 
Tropisternus lateralis. 
Philhydrus sp. 
StAPHYLINID/E. 
Creophilus villosus. 
NECROrHAGA. 
Acribis serrativentris. 
Phalacrus darwinii. 
Dermestes vulpinus. 
CURCULIONin.K 
Otiorhynehus cuneiformis 
Anclionus galapagoensis. 
Longicorxia. 
Eburia amabilis. 
Heteromera. 
Stomion helopoides. 
„ laevigatum. 
Ammophorus obscurus. 
„ cooksoni. 
„ bifoveatus. 
Pedonoeces galapagoensis. 
„ pubescens. 
Phaleria manicata. 
Anthribid^e. 
Ormiscus variegatus. 
Phytophaga. 
Diabrotica limbata. 
Docema galapagoensis. 
Longitarsus lunatus. 
Securipalpes. 
Seyran us galapagoensis. 
