BLOOD SUPPLY OF THE LUNGS 247 



lung, of less diameter than the vessel itself. At the periphery of 

 the lobule the capillaries converge to form several venules which 

 unite to form larger veins in the interlobular tissue. These veins 

 pursue an independent course and are always found at a consider- 



FIG. 210. FROM THE LUNG OF A DOG WHOSE BLOOD-VESSKLS HAD BEEN INJECTED WITH 



A GELATINOUS MASS, AND APPEAR BLACK. 



The outlines of the pulmonary alveoli and infundibula are well shown. Many of 

 the alveoli have been cut tangentially and present a surface view of the capillary net- 

 work ; in others the alveolar wall is cut across and is seen in profile, x 125. 



able distance from the bronchioles and lobular branches of the 

 pulmonary artery. 



The smaller branches of the pulmonary artery near the surface 

 of the lung give arterial twigs to the adjacent portions of the 

 pleura. From the capillaries of the pleura minute venules enter 

 the interlobular tissue and join the interlobular veins. 



The interlobular veins (pulmonary veins) follow the fibrous 

 septa toward the hilum. They soon come into relation with the 



