WATER RELATIONS OF OTHER SPECIES 



135 



-80 -70 



-60 



-30 



-20 -10 



Fig. 82. 

 (% of B„). 



-50 -40 

 Eate of initial gain of water (% of Bo/24 hours) in relation to water load 



Terrestrial snail, Limax, four species. For each point an individual weigh- 

 ing 1 to 15 gm. is desiccated for 3 to 16 days; then placed for 24 hours where water 

 is available. The line represents the theory that intake in 24 hours equals deficit. 

 Data of Kiinkel ('16, p. 88 ff.). 



"§> 46. Helix 



Many species of the shelled pulmonate snail Helix were sub- 

 jected to desiccation. These desiccations with privation of water 

 often lasted for months, involving therefore deficits of other sub- 

 stances as well as of water. ''If water and food are available to 

 the snails after desiccation, they begin to eat only after they have 

 drunk" (Kiinkel, '16, p. 86). 



In three species (fig. 83) the returns approximately equal the 

 deficits. "The quantities of water that can be drunk by the snails 

 depend on the water content that the animals have before drinking" 

 (p. 51). 



Additional observations show that water is taken through the 

 body (mantle) wall as well as through the mouth. Kiinkel believes 

 that both paths are ordinarily used. By both paths water appar- 

 ently ceases to enter when the control volume of the body has been 

 approximately reattained. 



