The right lymphatic trunk nearly equals the thoracic duct in diameter; it is, however, not more than half an inch in length. Its situation is in the neck at the level of the lower edge of the seventh cervical vertebra, where it will be found lying upon of the subclavian vessels close to the inner edge of the scalen us anticus muscle, and opposite to the union of the subclavian and internal jugular veins, at which point it termi nates in the venous system.
The right lymphatic trunk receives the lym phatics of the right upper extremity and of the right side of the head and neck, those from the right lung and right side of the heart, some few from the right lobe of the liver, and from the exterior and interior of the right upper half of the body.
Some of the principal branches which ordi narily empty themselves into the right lym phatic trunk occasionally terminate separately in the internal jugular or subclavian veins close to their junction. When these vessels all enter the veins separately, then the right lymphatic trunk is said to be deficient.
having described the position of the trunks of the lymphatic system as well as the situa tions of the conglobate glands in the various parts of the body, I now proceed to trace the vessels themselves.
I shall commence with the description of the lymphatics of the lower extremities, as being the most remote from the trunks of the system. They are divided, as in all other parts of the body, into a superficial and deep-seated set, which latter accompany the principal bloodves sels. They are associated successively with the digital arteries, the internal, external plantar, and dorsal arteries of the foot ; in the leg with the anterior, posterior tibial, and fibular vessels.
At least two lymphatics, which are united frequently by short branches crossing from one to the other, accompany each of these arteries, and all are ultimately conducted by the blood vessels to the popliteal glands, in which they terminate. The vasa efferentia of these glands, from two to six in number, entwine around the popliteal and femoral vessels, having frequent communications with each other by short cross branches, until they reach the inguinal region, where they terminate for the most part in the deep-seated cluster of inguinal glands; one or more, however, may reach the superficial glands or even those accompanying the external iliac artery above Poupart's ligament. The deep seated lymphatics in their course are joined by branches which have accompanied the principal ramifications of the bloodvessels ; they also at various points form communications with the superficial lymphatic vessels.
The superficial lymphatics of the lower extre mities may be divided into two groups; one con sisting of numerous vessels which follow more or less the course of the saphena major vein and terminate in the inguinal glands; the other com posed of but few vessels, which, accompanying the saphena minor vein, join the popliteal glands. The latter take origin from the dorsal surface of the little toe and from the outer edge of the dorsum and sole of the foot ; they proceed with the branches of the saphena minor vein in the direction of the external malleolus, from thence to the outer edge of the tendo Achillis, where they glide with the vein under the fascia of the leg to reach the centre of the gastrocnemius muscle, between the heads of which they dip to join the popliteal glands. The superficial
lymphatics which accompany the saphena ma jor vein commence on the dorsal surface of the toes, where they communicate with the digital lymphatics. On the dorsum of the foot they ascend in from three to six branches; the most internal mount over the internal malleolus with the branches of the saphena major vein to the inside of the knee; the most external pass over the external malleolus and outer side of the leg, at a higher or lower level however, they are directed inwards and pass over the spine and inner surface of the tibia to join the former, at the inner side of the knee ; those from the centre part of the dorsum of the foot ascend in front of the tibia ; these also soon tend inwards to be associated with the rest.
Another set take origin from the sole of the foot and proceed upwards on the back of the leg superficial to the fascia, having communi cated freely with the lymphatics accompanying the saphena minor vein. These also sooner or later turn inwards to gain the inside of the knee. From these sources some twelve or fif teen branches may be enumerated, which con tinue to ascend on the inside of the thigh wit the saphena major vein. Some few pass and the fascia lata to join the deep-seated vesse From the back of the leg and thigh they recei an accession to their numbers of several vessel. the most of these reach them from the inside, b some few from the outside of the limb. Th ultimately terminate in the superficial dust of glands in the groin. Some few, howev may dip down to join the deep-seated glan and to unite with the deep-seated lymphati One may occasionally be seen to pass the in guinal glands to reach those accompanying t external iliac artery., The inguinal glands also receive the super ficial lymphatics from the genitals, from the lower half of the anterior and posterior part of the trunk, from the perineal and gluteal re gions. The lymphatics of the scrotum collect into one or two branches, which take their course with the superficial pudic veins to reach the glands in the groin. _Chose of the penis commencing on the glans and prepuce pro ceed generally in three principal branches on the body of the organ, two of are si tuated laterally, and the third on the centre of its dorsal surface. These three vessels not un frequently unite near the root of the penis into one vessel, which immediately divides right and left into branches, which also accom pany the superficial pudic veins to the inguinal glands. In the direction of the superficial epigastric and circumflexa ilii yells there are several lymphatics derived from the anterior and lateral parts of the abdomen, which empty themselves in the inguinal glands. The super ficial lymphatics from the perineal and gluteal regions, some from the loins and posterior and upper part of the thigh, stream round the outer part of the limb in the neighbourhood of the trochanter major to terminate in the same glands.