The Effect of Vitamin A Deficiency on Malposition of the Chick Embryo

MALPOSITION and mortality of the chick embryo has received a great deal of attention in recent years by research workers. The purpose of this research has been to determine the exact cause of mortality and malposition. Results to date are not in complete agreement as to whether mortality and malposition are due to environmental, nutritional, or inherited factors, or a combination of these sources. Hutt and Pilkey (1932) classified malposition of the chick embryo into six types, and made a study of 18 days’ incubation with eggs placed horizontally as compared with eggs with the large end raised 45 degrees. In eggs incubated horizontally, the frequency of malposition was 10.1 percent in embryos alive at 18 days, or 60.4 percent in those dying after that age. In eggs with the large end raised, the frequency of malposition was 10.7 percent in embryos alive at 18 days, or 65.9 percent in . . .