1908. | Diphtheria Antitoxin. 413 
indicate that this protein is added to serum during immunisation, and that 
the antitoxic property is not due to the addition of a group possessing this 
character to a normal protein molecule. This conclusion also follows from a 
study of the relation between total solid and antitoxic strength of the serum 
of a horse during its antitoxic life. 
It is suggested that one of the functions of the proteins composing the 
group albumin («) is to protect the tissues against disease. 
A theory is advanced that the production of diphtheria antitoxin is due to: 
an active secretion by the leucocytes, this secretion being stimulated by the- 
ingestion of toxin molecules. 
REFERENCES. 
(1) Brieger and Ehrlich, ‘ Zeitschr. f. Hygiene,’ vol. 12, p. 137. 
(2) Aronson, ‘Berl. klin. Wochenschr.,’ vol. 26, p. 425. 
(3) Brodie, ‘Journ. of Pathol. and Bacteriol.’ vol. 4, p. 460. 
(4) Freund and Sternberg, ‘ Zeitschr. f. Hyg.,’ vol. 31, p. 429. 
(5) Pick, ‘ Hofmeister’s Beitr.,’ vol. 1. 
(6) Szontagh and Wellmann, * Deutsche med. Wochenschr.,’ vol. 24, p. 421. 
(7) Hiss and Atkinson, ‘ Journ. of Exp. Med.,’ vol. 5, p. 47. 
(8) Ledingham, ‘Journ. of Hygiene,’ vol. 7, p. 65. 
