Effects of white light on the pineal gland of the chick embryo

Chick embryos were directly exposed to a source of white light during incubation and sacrificed before hatching. The light caused a number of teratological effects such as high mortality, delay in development, celosomy, hepatomegaly, auricular dilation and micrognatia. The pineal gland of the illuminated embryos showed an increase in number and size of the intracytoplasmic lipid droplets of the follicular pinealocytes. These findings suggest that the pineal gland of the chick embryo is sensitive to light.