28 THE DISPERSAL OF SHELLS. 



vivipara^ an operculate water-snail, as Mr. R. M. Christy 

 states, accidentally ejected from an aquarium and allowed 

 to remain for more than three weeks on the ground in 

 a field, on being restored to its fellows seemed to 

 have taken no harm.^ Some Anipullarice^ placed in a 

 drawer by Mr. Laidlay, are even said to have survived, in 

 the warm climate of Calcutta, for five years ! - A fresh- 

 water mussel {Aiiodonta) once arrived alive in France 

 after having been wrapped up in dry paper for eight 

 months during its voyage from Cochin-China,^ and 

 an Australian Unio, resembling our "swollen fresh-water 

 mussel" {Unio tuinidus)^ having already survived in a 

 dry drawer for 231 days, packed up (after being tested 

 in water) and forwarded to England, reached South- 

 ampton in a living state 498 days after its capture, and 

 was subsequently " restored to its element, with full vital 

 powers," in the care of Dr. Baird, of the British Museum.^ 

 This great tenacity of life, common to many kinds, of 

 which quite a number of instances might be given,*^ 

 must certainly have largely facilitated dispersal. 



1 R. M. Christy, "Zoologist," (3), v. (1881), 181. 



2 Woodward's " Manual," ed. 4, rep., 1890, p. 14. 



3 " Journ. de Conch.," xxiii. (1875), 81-4, as quoted in "Quart. 

 Journ. of Conch.," i. p. 78, and "Zoological Record," xii. (1875), 

 136. 



•* Probably, according to Mr. Musson, U. ambigiius or U. 

 aiistralis. 



^ J. S. Gaskoin, " Proc. Zool. Soc," 1850, pp. 243-4, and see 

 also Woodward's " Manual," ed. 4, rep. 1890, pp. 13-14. 



^ See, for example, J. L. Hawkins, on Liiimaa stagnalis, 

 " Science Gossip," xvii. (1881), 23 ; Jeffreys, on Sphceriuin lacustre, 

 "British Conchology," i. (1862), 11-12 ; Baker Hudson, on SpJtce- 



