Structure and Ultra-Structure of the Hen's Egg Shell as Influenced by Environmental Temperature, Humidity and Vitamin C Additions

Abstract

INTRODUCTIONTHE strength of the hen's egg shell is of economic importance as handling and transportation entail the danger of breakage. The avian egg shell is composed of four layers, the outermost being the cuticle (taken here in the sense of Tyler, 1964), followed successively by the calcified spongiosa, the likewise calcified mammillary layer and innermost the membranes. Its structure and ultra-structure were studied under the microscope and electronmicroscope respectively. Of course the thickness of the shell determines its strength to a great extent. But its domed architecture supported by the radially arranged crystal columns in the mammillary layer and spongiosa will also contribute, as may also be the case with the organic matrix intermingled with the calcareous deposits in the shell and with the fibrous membranes in which the mammillae are embedded.REVIEW OF LITERATUREEgg shells are of greatest and most uniform thickness in winter and become thinner .