An incidence of a complete separation of the lower lobe of right lung from the rest of upper part, as observed in a cadaver in the anatomy dissection hall.

evelopmentally each lung-bud projects into the pleural coelom. The splanchnopleuric layer of lateral plate mesoderm invests each lung-bud and develops into pulmonary pleura. The right principal bronchus divides into three secondary bronchi, around which the lobes of the lungs are developed. The left principal bronchus divides into two secondary bronchi, around which the two lobes of the left lungs are developed. The oblique and transverse fissures do not completely cut through the lung mass. But in the present case the lower lobe of the right lung is completely cut off form the upper and middle lobe above it by the oblique fissure. The pulmonary pleura completely covers the whole upper surface of the separated lower lobe. The lowermost of the three secondary bronchi supply this lobe separately. A branch of the right bronchial artery could be traced behind this secondary bronchus. D Showing the mediastinal surface of upper and middle lobe completely separated from the lower lobe The two separated parts of the lungs are held nearer each other