Egg Turning, Pipping Position and Malpositions

THE ability of the chick embryo to orient itself within the shell prior to hatching time is a subject of dispute. Hutt and Pilkey (1934) stated that if eggs are placed horizontally on a tray on the eighteenth day, and not turned subsequently, all eggs which hatch are pipped on the upper surface. They stated further that eggs turned on the nineteenth and twentieth days are pipped about equally on upper, lower, and intermediate surfaces. They presented no data to support their statements. Waters (1935a) presented data for 225 eggs turned four times daily after the seventeenth day and for 225 controls not turned after the seventeenth day. The turned eggs were pipped about equally on all surfaces, as Hutt and Pilkey stated, but the unturned eggs were also pipped about equally on all surfaces. Byerly and Olsen (1936) reported that about 5 percent of eggs not turned after the . . .