134 THE DISPERSAL OF SHELLS. 



inhabiting the coast-lands of the Fiji group, and common 

 to most of the islands, living as they do, '^sheltered by 

 bark on logs^ and in the decaying husks of old cocoa- 

 nuts," are probably frequently transported from island 

 to island.' As indicating a possibility of actual trans- 

 plantation by means of agencies of the present kind, it 

 is interesting to note that drifted trees are known to be 

 occasionally left by storms on island or foreign coasts, 

 high and dry, out of the reach of the ordinary tides. 

 Mr. C. T. Simpson, as just quoted, states that he 

 has seen trees thus stranded on the island of Utilla, and 

 on the shores of Florida. Charles Goodridge, who 

 stayed some time in the Crozet Islands in 182 1-3, de- 

 scribed the discovery of several tree-trunks, lying on 

 the ground as if thrown up by the sea, more than a 

 mile from the reach of the tides. The wood was 

 evidently not fossil, and " Goodridge concluded that it 

 was drift-wood thrown up so far during some volcanic 

 convulsion." - It will always be remembered, of course, 

 that complete protection from sea-water during long 

 periods will hardly ever be afforded by floating timber, 

 and thousands of inland molluscs must annually perish 

 in the sea ; partial protection, however, both for adult 

 animals and ova, must often be afforded for a consider- 

 able time, and some snails, as we have seen, can with- 

 stand total immersion for short periods. Trees, 



^ E. A. Liardet, " Proc. Zool. Soc," 1876, p. 99. 



^ C. M. Goodridge, " Narrative of a Voyage to the South Seas, 

 etc.," pp. 42-3, as quoted by Mr. Moseley, " Naturalist on the 

 Challenger, ^^ 1879, PP- 182-3. 



