Developing lung (labels) - histology illustration

Section of lung of pig embryo, 13 cm. long, showing the glandular character of the developing alveoli (J. M. Flint.) X 70. a. Interstitial connective tissue. b. A bronchial tube. c. An Alveolus. l. lymphatic clefts. q. Pleura.

Histology illustration courtesy of Gray's Anatomy.