The Biology of the Cell Surface

Abstract

DR. JUST has written an interesting account of his personal views on a group of subjects including fertilization, cell division, and the function of chromosomes. The first part of the book, dealing mainly with the structures, functions, and movements of the ectoplasm (the outer layers of the protoplasm) of marine eggs, contains a large amount of material on which there, is fairly general agreement. The following chapter, on water, deals with the movements of water in eggs, and between eggs and their environment. It is stated that when eggs are placed in hypertonic saline, water leaves the egg in discrete droplets, which apparently have to pass through comparatively narrow channels in penetrating the ectoplasm. This extremely interesting observation, if confirmed, would invalidate the majority of the work which has been done on the permeability of marine eggs, in which it is assumed that water leaves the egg by simple diffusion. In the same chapter, Dr. Just betrays some doubt as to the existence of a relatively impermeable membrane at the surface of the cytoplasm. There is to-day no ambiguity on this point; the impedance studies of Cole (J. Cell. Comp. Physiol., 1, 1; 1932; J. Gen. Physiol., 18, 877; 1935) have shown that such typical eggs as those of Arbacia and Hipponoe have a membrane which is impermeable to ions, while Chambers (Biol. Bull., 69, 331; 1935) has shown by microdissection that this membrane is liquid and fatty in character.

The Biology of the Cell Surface

By Ernest Everett Just. Pp. xi + 392. (London: The Technical Press, Ltd., 1939.) 26s. net.