Hatchability of Eggs Set Small End Up

In a study dealing with respiration of the hatching chick, a large number of embryos was needed which would hatch without access to the air cell. Eggs were incubated with the small end up in order to induce the malposition “head-in-small-end.” In this position the embryos have no access to the air cell. Procedure: A total of 1197 eggs was incubated small end up for five different periods of time during the first eighteen days of incubation; otherwise they were in normal positions. A small set of 117 eggs was used as a control which was set normally during these 18 days. All eggs were on their sides in the hatching trays during the last three days of incubation. They were candled on the 6th and 14th days. The relative position of shell pipping was recorded starting on the 19th day. The unhatched eggs were opened, and their embryos were …