THE LYMPHATICS OF THE PELVIS. 987 



is developed on either side of the frenulum {Panizza s plexus), from which stems 

 ascend in the groove back of the corona glandis. Into these stems the superficial 

 layer of the net-work opens, and they also receive communications from the super- 

 ficial vessels of the penis. From them one or two stems arise which pass proximally 

 in company with the dorsal vein of the penis toward the suspensory ligament. Here 

 they usually divide to form a more or less distinct plexus, lying immediately over 

 the symphysis pubis and provided with some small lymphatic nodes, and from it two 

 or three stems pass off laterally on either side. These pass across the surface of the 

 pectineus muscle and beneath the spermatic cord, and some then pass either to the 

 inner inguinal or deep subinguinal glands, while others extend along Poupart's 

 ligament to the external abdominal ring and, traversing the inguinal canal, terminate 

 in one of the lower iliac nodes. 



It is to be noted that owing to the anastomoses and bifurcations of both the 

 superficial and deep longitudinal stems it is possible that a unilateral infection may 

 cause enlargment of the nodes of both sides. 



The External Reproductive Organs in the Female. — The lymphatics of 

 the external female genitalia have essentially the same distribution as those of the 

 corresponding organs in the male. In both the labia majora and minora rich 

 subcutaneous net-works occur, from which numerous stems arise and pass to the inner- 

 most inguinal and occasionally the inner superficial subinguinal nodes. The stems 

 from the upper parts of the labia ascend at first directly upward toward the mons 

 veneris and then bend suddenly outward to reach their terminal nodes ; those from 

 the lower parts pass either directly upward and outward or else at first directly 

 upward parallel to the outer edges of the labia and then bend suddenly outward. 

 Some of the stems coming from one or other of the labia may pass to the nodes of 

 the opposite side, and, furthermore, communications exist through the anterior and 

 posterior commissures between the net- works of the opposite labia, so that a unilateral 

 infection may produce enlargement of the inguinal nodes on both sides. 



The lymphatics of the clitoris present essentially the same arrangement as the 

 deep lymphatics of the penis. They form a rich net-work in the glans and from this 

 longitudinal stems arise and pass toward the symphysis pubis, in front of which they 

 form a plexus which usually contains some small nodes. From the plexus «6tems 

 arise which pass laterally, and terminate either in one of the deep subinguinal nodes 

 or else in the lower iliac nodes, which they reach by traversing the inguinal canal. 



The Perineum and Circumanal Regions. — The deeper lymphatics of these 

 regions have been considered in connection with the organs to which they belong 

 and there remain for consideration only the subcutaneous vessels. These in the 

 perineal region form an abundant net-work from which stems pass forward, for the 

 most part in the furrow between the perineum and the inner surface of the thigh, 

 and, associating themselves with the stems from the scrotum or labia majora, 

 terminate in the inner inguinal or superficial subinguinal nodes. 



The subcutaneous lymphatics which surround the anal opening also form a rich 

 net-work, which communicates extensively with that of the anal mucosa (page 979). 

 From it some two or three stems pass forward along the inner side of the thigh to 

 terminate with the perineal and scrotal (labial) stems in the inner inguinal nodes. 



The Internal Reproductive Organs in the Male. — The testis possesses an 

 abundant supply of lymphatics, which may be divided into a deep and a superficial set. 

 The former takes its origin in a rich net-work which surrounds the seminal ducts, and 

 the stems which compose it pass toward the hilum in the septa, and, issuing, associate 

 themselves with the stems arising from the superficial net-work. This is double, one 

 layer of it lying beneath the tunica albuginea and the other between that investment 

 and the visceral layer of the tunica vaginalis. Both layers are abundantly connected by 

 vessels which traverse the tunica albuginea, and the deeper layer also receives numer- 

 ous communicating stems from the deep lymphatics and from the lymphatics of the 

 epididymis. Collecting stems from both layers converge toward the hilum, where they 

 become associated with the stems from the deep net-work, from six to eight or rarely 

 more trunks which ascend along the spermatic cord to the internal abdominal ring. 

 They then follow the course of the spermatic veins upward, and terminate in from two 

 to four of the lateral lumbar nodes (Fig. 816). The nodes to which the vessels from 



