While the alveolar macrophage has been studied extensively, little attention has been directed toward the immune functions of the bronchoalveolar lymphocyte. These cells, obtained by bronchopulmonary lavage of the normal canine lung, are derived from the air side of the alveolar-capillary membrane of the lower respiratory tract. The distribution of lymphocyte types within the bronchoalveolar cell population was determined and compared with that of leukocytes from blood and spleen.
