Note on a System to Evaluate the Influence of Chronic Exposure to CO on the Hatching Eggs of the White Leghorn Chicken

It has become increasingly apparent that there exists a need for evaluating the well-being of embryos subjected to chronic doses of CO during gestation. Baily¹ and Hadden,² for example, have reported that maternal cigarette smoking resulted in a significant decrease in infant birth weight. It is obvious, however, that the presence of other pharmacologically toxic substances in cigarette smoke besides carbon monoxide may have been significant. A problem in using the developing mammalian embryo as a model for studying the effects of such agents is that the physiological responses of the mother may afford some measure of protection to the developing fetus. This is not the case in oviparous development because there is no connection between mother and embryo.