CHAPTER VIII. 



DISPERSAL OF FRESH-WATER AND LAND MOLLUSCA 

 BY MAN. 



In comparatively recent times many molluscs have 

 been widely scattered over the globe by man. Indeed 

 it may be safely said that both snails and slugs, during 

 the last three centuries at least, have been more 

 dispersed by human agency than by all other causes 

 together. European species, for instance, thus dis- 

 seminated, as everyone knows, have become thoroughly 

 naturalized in many parts of the world, even in the 

 most remote colonies.' Many facts illustrating the 

 extent to which certain faunas have been alloyed by 

 man might be given. All the species of Limax 

 described as native to Australasia are referable, accord- 

 ing to Mr. Hedley, either to L. niaxinms, flavus, 

 gagates^ agrestis, or Icevis^ all, except the last, believed to 

 have been introduced by man from Europe." The 

 Madeiran Islands, to give another instance, discovered 



' See Woodward's "■ Manual," ed. 4, rep. 1890, p. 289. 



- C. Hedley, "Ann. and Mag. Nat. Hist.,'' (6),ix. (1892), p. 170 ; 

 C.T. Musson, " Proc. Lin. Soc, N.S.W." for 1890 (2), v. (1891), 

 p. 885. 



