A Study of the Changes in the Blood and Blood-forming Organs Produced by Cytotoxic Sera, with Special Reference to Hæmolymphotoxin

(1) The cytotoxins are not specific. (2) The changes occurring after the injection of different cytotoxins are similar and do not vary in kind. (3) The changes do, however, vary in degree in the following order, the one having the most marked effect being placed first, etc.: (a) Haemolymphotoxin, (b) Splenotoxin, (c) Lymphotoxin, (d) Endotheliotoxin, (e) Nephrotoxin, (f) Hepatotoxin. (4) Nephrotoxin causes the most specific change. (5) The haemolymph glands play some important part in the production of eosinophiles. The haemolytic action of haemolymphotoxic serum is greater than that of other cytotoxic sera. (6) The histological changes which are observed in every case are secondary to the haemolytic factor present in all cytotoxic sera.