The normal egg, then small amount of albumen and shell and outside shell. Soft shelled eggs are more prevalent in the springtime heavy laying season. Being laid prematurely before secretion of shell in the uterus or some physiological disturbance in the laying hen. Due to part calcium for the shell formation was not secreted at same rate as the albumen. Inner and outer shell membrane are secreted.
Some eggs have blood clots, pieces of tissue of the oviduct or some rare cases, worms.
Blood clots are due to hemorrhage of the oviduct or hemorrhage in the ovary, from which blood escapes and is enclosed in the albumen in the shell membrane and shell. The worms are present when they escape from the intestinal tract into the body cavity and gaining entrance to the oviduct and being enclosed in the egg. Thus a need to worm the birds twice a year to rid the body of these pests. Especially before hatching time comes around. The egg being a closed system.