Radioautographic study of mesenchymal cell activity in the secondary palate of the rat

In this radioautographic study of the developing secondary palate of the rat, it has been shown that there was not the increased nuclear labeling indicative of increased mitotic activity in the mesenchyme said to be responsible for medial rotation of the palatal shelves. Variations in labeling index in different regions of the developing palate appeared mainly because of developing bone and mucous glands.