Abstract
Perinatal changes in the sublingual gland of the rat were studied by histometric observation of acinar cells and their mucus. The sublingual gland accumulated mucus until the end of fetal life and showed a transient marked decrease in the amount of mucus immediately after birth. These changes in the amount of mucus were accompanied by corresponding morphologic changes in acinar cells. Insertion of a cotton ball into the oral cavity of a premature newborn pup delivered by Caesarean section one day before birth caused a marked decrease in the amount of mucus. The results suggest that rapid secretion of mucus of the sublingual gland occurs just after birth owing to a physical stimulus given to the oral cavity and that the ability of the gland to respond to the physical stimulus is established at least one day before birth.
