I/O THE DISPERSAL OF SHELLS. 



their way into the decaying wood, for several specimens 

 of L. niaxiinus, found when removing rubbish and 

 breaking away parts of the wood from a cavity in the 

 trunk of an old hornbeam, subsequently extruded pale 

 yellow pellets composed entirely of "saw-dust." In 

 these situations the creatures would often be well pro- 

 tected, so that they might be carried in safety with 

 floating trunks to great distances. Many kinds, it must 

 not be forgotten, live mostly on the ground, rarely or 

 never ascending trees, and these of course are not likely 

 to be carried with timber, unless they occasionally hide 

 themselves in logs lying upon the ground ; they must 

 frequently be swept in numbers from their haunts on 

 grassy or muddy river-margins, but unless buoyed up by 

 some object, they are not likely to be much dispersed by 

 the currents, for I believe they always sink in water, and 

 when carried away by the rushing waters of torrents or 

 floods are hardly likely to be often landed again in a 

 living state. It seems probable, however, that they 

 may sometimes be safely floated upon vegetable-rafts 

 of many sorts. A few years ago, indeed, I had the 

 good fortune to witness the conveyance of a slug by 

 this means, upon a very fragile raft. Walking in the 

 evening from the Lincolnshire coast towards Louth 

 along the banks of the Eau, I saw a large black slug 

 [Ai'ion ate/-) crawling with out-stretched tentacles upon 

 a mass of " green-scum '■* which came drifting down with 

 the current at a good way from the bank. This was at 

 no great distance from the sea, and in all probability the 

 animal was ultimately carried out and drowned, but pos- 



