MEANS OF DISPERSAL. I47 



V. vtargaritacea, Helix aciileata, H. pygmcea, Vertigo 

 substriata^ V. edentula^ and CarycJiiiim niiniuiuin — from 

 moist leaves, chiefly those of beech and holly ; but in 

 the same locality, in September, when the weather was 

 hot and dry, a careful examination of four handfuls of 

 leaves, which were quite dry and might have been 

 carried away by a strong wind, yielded only a solitary 

 Vertigo ; this, however, on being moistened, was found 

 to be alive. 



In Germany, according to Mr. Daniel, the Helix acu- 

 leata, travelling high up into trees, particularly the alder, 

 reaches the ground in autumn on the falling leaves. 

 Helix fusca, too, M. Bouchard-Chantereaux states 

 inhabits alders in the woods near Boulogne, hiding on 

 the undersides of the leaves, and falling with them in 

 September and October.^ Snails with habits of this kind, 

 obviously, might be carried to considerable distances 

 when leaves, instead of falling directly to the ground, 

 happen to be blown off during autumn gales. 



Many small snails are so light that they could cer- 

 tainly never impede the flight of leaves to which they 

 happened to be more or less securely attached ; twelve 

 " mature specimens '' of Vertigo militim^ for instance, 

 a species found gregariously under or among dead leaves, 

 and measuring only four-fifths of a millimetre in length, 

 are stated by Professor Adams to weigh less than six- 

 tenths of a grain." 



^ " British Conchology," i. (1862), p. 176 : and p. 206. 

 - A. Binney, "Terrestrial air-breathing Molhisks," ii. (1851), p. 

 338, 



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