392 The Vascular Supply of the Pleura Pulmonalis 
The present study of the pleural blood-vessels has brought out one point 
which I overlooked at the time I studied the lymphatics of the pleura 
(9c), and which I do not find mentioned or illustrated in any previous 
contribution to the histology of the lung, namely, a distribution of 
blood-vessels to the lymphatics. 
Fig. 2. Surface view of the pleura of the lung of a dog. P. A.= pulmonary 
artery. P. V.—pulmonary vein. The pulmonary artery is seen arching under 
the pleura and giving off branches to the pleura. The characteristic branch- 
ing of the pulmonary veins is also shown. Camera lucida tracing. Details 
omitted. x 50. 
From the radicles of the pulmonary artery, which extend to the pleura, 
branches are given off which arrange themselves parallel to the course 
of the lpmphatics. Generally, there is a blood-vessel on each side of a 
lymphatic; these are connected at intervals by transverse branches which 
run external to the lymphatic. There is thus formed a network of blood 
vessels the mesh of which is roughly rectangular, the long axis of the 
rectangle being placed at right angles to the course of the lymphatic 
(Fig. 3). 
