Studies on egg shells. VII.—Some aspects of structure as shown by plastic models

Abstract

Abstract When egg shells are embedded in plastic it would appear that the plastic can form a clean mould of the inner surface of the shell with its knob‐like projections, it can also penetrate into the pore channels and even into the body of the shell itself. The shell can then be dissolved away leaving the plastic moulds behind. It is thus possible to obtain a clear picture of the shape and size of pores and their relationship to the air spaces in the mammillary layer. The egg shells of various species of birds have been examined and differences in pore size and shape clearly demonstrated. The plastic residue from the shell itself also seems to indicate that the shell consists of layers of material, the layers being arranged differently in different species.