The spawn of five Stylommatophora, one basommatophoran, one prosobranch and one opisthobranch were each desiccated at 25 °C and at various constant relative humidities, and in almost still air. The experimental apparatus incorporated glass “fishpole” balances and a time-lapse cine-camera. Differences in desiccation rates were found to be due to differences in size of the experimental objects, the larger egg-masses losing water at a relatively slower rate than the smaller.

At equilibrium with the atmosphere the marine spawn retained more water than those from other habitats. Different water-retaining capacities probably reflect interesting biophysical characteristics of the mucus of different species.