resulting in smaller orders. Two types of tubules can be demonstrated; the future bronchial and acinar tubules. In rabbit fetuses of 80-105 mm CVRL, the lobes are well distinct and separated by deep interlobar fissures. The acinar tubules communicate forming acinar canals which are lined by epithelial cells of different shapes. The interstitial connective tissue reduces in amount and becomes more condensed. In rabbit fetuses of 110-130 mm CVRL, the lung occupies most of the thoracic cavity. The primitive alveoli are lined by two types of cells alveolar epithelial cell type I and II. Many blood capillaries insinuate within the lining epithelium of alveoli Disintegrated and sloughed epithelial cells are demonstrated in the conducting portion of the lung The morphometric study indicates that the height of epithelium of both conducting and respiratory portions of fetal rabbit lung is decreased with the advancement of age.