VARIATIONS IN THE WATER AND MINERAL CONTENTS OF SOME ORGANS OF THE SNAIL, HELIX POMATIA L.

Abstract

The water content of the digestive gland, foot, albumen gland, and dart sac of Helix pomatia tends to vary inversely with the concentration of sodium in the blood. That of the albumen gland depends also on size, for, having achieved a dry weight of 0.013 g, the gland continues its growth by the addition of a component containing only about 57% water. This stage is reached when the dry weight of the rest of the snail, less its shell, is about 1.2–1.8 g. The dart sac contains much more potassium than sodium or magnesium and the concentrations of potassium and of magnesium vary inversely with the amount of water in which they are dissolved. The columellar muscle resembles the dart sac in its potassium content (per kilogram dry weight) but contains more water and sodium.