The Penetration of Some Non-Polar Molecules in Solution Through the Egg-Shells of Locusta Migratoria Migratorioides and Teleogryllus Commodus

Abstract

ABSTRACT The micropylar ends of eggs of Locusta migratoria migratoria were cut off, the tissues were removed, and the empty egg-shells were filled with water or with a solution. The open end was tied off to form a balloon. Balloons containing water were placed in a solution, and those containing solution were placed in water. Balloons containing glucose solution swelled in water and those placed in glucose solution shrank. Little change was observed either in balloons containing urea or in those placed in urea. Results with solutions of malonamide were erratic. Empty egg-shells of Teleogryllus commodus were perfused with radioactive solutions of substances of varying hydrated molecular radii. The smaller molecules (acetamide and urea) passed through the shell into the surrounding liquid more rapidly than the larger ones (glucose and ribose). Shells in which the serosal cuticle was absent were more permeable than those in which it was present. Molecules penetrated living eggs much less readily than they passed out through dead egg-shells. The results are discussed in relation to the permeability of the shells of insect eggs to water and their capacity to restrict the leaching of molecules from the tissues of the egg.