The fine structure of the pores in the shell of the hen's egg

No fibrous or crystalline material was present in the lumen of pore canals which were exposed by radial fracture and examined with a scanning electron microscope. The walls of the canals were rough, but they did not have a characteristic ultrastructure. The campanulate outer orifice of the pores was plugged with cuticle in which radial cracks formed channels through which the respiratory gases presumably diffuse.