Studies of the lymphatic tissue. II. The first appearance of the secondary nodules in the embryology of the lymphatic tissue

The Role of the Lymphocyte in the Circulation of the Lymph

“…They are the first lymphatic nodules to appear, and, in man, have been found as early as in the 22nd fetal week. 16 The diameter of these nodules does not usually exceed 0.3 mm.…”

“…Tertiary nodules may be observed even in fetal life. 16 Primary and secondary nodules, on the one hand, and tertiary nodules, on the other, differ greatly in their blood supply. Primary and secondary nodules are usually supplied by an arteriole and the arterial portions of its capillaries, while veins are completely absent (PLATE 8) .…”

Studies of the Lymphatic Tissue

“…Beside the popliteal lymph nodes the axillary, retroperltoneal, mesenterle lymph nodes, the lymph nodes of the intestine and the spleen were studied. The organs were fixed, cut and stained, as described in a previous paper (1).…”

“…of a 48 hour broth culture of Staphylococcus aureus of especially low virulence (obtained from the surgical clinic in Freiburg) diluted with equal parts of saline solution. At 2,4,6,9,12,18,21 and 29 days after injection leucocyte counts were made on all animals still living. R 15 was killed after 2 days, R 14 after 4, R 16 after 6, R 12 after 14, R 13 after 21 and R 11 after 29 days.…”

“…In two papers published elsewhere the cellular structure of the secondary nodules (1) and their embryological development in human beings (2) have been described. It was found impossible to accept the conception formulated on Flemming's original theory that Flemming's secondary nodules are the places of formation of the lymphocytes of the blood, or to accept even a modification of this theory without some doubt.…”