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These are very numerous. Arising at the surface of membranes and in the tissue of the organs, they carry into the veins the lymph from those parts. Lymphatic vessels are found in every part of the body. Wherever they are met with, however, they form two orders,-one superficial, the other deep-seated; - the two orders frequently communicating with each other. Lymphatic vessels are generally smaller than arteries and veins. They are very thin, diaphanous, and cylindrical; but present, here and there, more or less considerable dilatations, caused by valves in their interior. They are slightly tortuous in their course; their anastomoses are very numerous, and they often cross each other, forming successive plexuses. Of the arrangement of the extreme radicles we are ignorant. All the branches, before joining the principal trunks, pass through lymphatic ganglions, in which they are convoluted, or subdivided almost ad infinitum. They are formed of an outer areolar membrane and an internal coat, similar to that of the veins; of the latter, the valves are formed. All the lymphatics of the body ultimately discharge themselves at the junction of the subclavian and internal jugular veins. Two of these trunks are considerably larger than the others, - the thoracic duct, and the great trunk of the right side, (F.) La grande veine lymphatique droite. The former receives the lymphatics of the abdomen, of the lower extremities, the left side of the thorax, the left upper extremity, and the corresponding side of the head and neck; the latter receives those of the right upper extremity, and of the right side of the head, neck and thorax.

vessels that convey lymph.