Studies on egg shells. XVII.—variations in membrane thickness and in true shell nitrogen over different parts of the same shell

Variations in membrane thickness and in total, insoluble and soluble nitrogen in the true shell over different parts of the same shell have been considered. For membrane thickness the variations around any particular latitude were much smaller than variations along any longitude. Variations around any one collar were greater for membrane thickness than for shell thickness and greater for total nitrogen than for membrane thickness.