Permeability and Properties of the Membranes Surrounding the Developing Egg Of Homarus Vulgaris

Abstract

Subjection to a variety of fluids confirms the presence of two non-living membranes roundv the developing eggs of Homarus. It also reveals that the outer membrane has the restricted permeability of cuticle and the inner membrane the free permeability of chitin.The inner, chitinous membrane bursts when the egg contents swell; the outer membrane stretches, up to 50 % above its initial diameter, when the internal osmotic pressure rises. It also has considerable elasticity.These properties of the outer membrane enable it to withstand the pressure to which the developing eggs are subjected and also to stretch during the development of the embryo, hence they have,considerable biological significance.The inner, chitinous membrane, which does not stretch, is probably ruptured and absorbed during development.