Anatomical study of the pulmonary lymphatics.

As the result of anatomical as well as histological investigations on the lymphatics of the human lung, the authors have arrived at the following conclusions: 1. According to the distribution and the direction of lymph flow, pulmonary lymphatics are classified into two systems and four groups. 2. The lymphatics cannot be found in the interalveolar septum. 3. The extravascular fluid pathway system plays an important role for cleaning particles in the most peripheral part of the respiratory tract where no lymphatics are found. 4. Efferent lymph flow reaches the venous angles via two routes on both sides respectively.