Frederick G. Parsons and Harriette L. Hennessy, 1911 Encyclopædia Britannica, Volume 17… (1911)
“ The vessels divide and anastomose very freely, and for this reason they do not, like the veins, increase in calibre as they approach their destination. It is usual to divide the lymphatic vessels into a superficial and a deep set; speaking generally, the superficial ones are found near the course of the superficial veins, while the deeper ones accompany the arteries. Probably any single drop of lymph passes sooner or later through one or more lymphatic glands, and so those vessels which are approaching a gland are called afferent, while those leaving are spoken of as efferent lymphatics. ”
