Specific Complement Fixing Antibodies. 295 



crease in the number of antibodies. A sufficient number of these 

 bodies, however, were present during the May determination to 

 merit the designation of 3 plus (+ + +) with the usual complement 

 fixation technique. 



The case of Rabbit A, immunized with 0.5 gm. of protein 

 showing in its blood the presence of complement fixing anti- 

 bodies five months after immunization, is of significance inasmuch 

 as it revives the old disputed question as to the nature of the com- 

 plement fixing antibody. The widely accepted view that this anti- 

 body is an indication of the presence of an active antigenic mani- 

 festation in the body as differentiated from the agglutinin, for 

 example, which is a true antibody, is brought to question ; since 

 one would have to assume that some of this small quantity of 

 protein is present in the animal in some form, after 5 months — 

 a quite unlikely condition. 



152 (1734) 



Influence of radium and x-rays on the frog's leucocytes. 



By M. M. STURGES and ISAAC LEVIN. 



[From the Department of Cancer Research, Montefiore Hospital, 



New York.] 



The white blood corpuscles are the most sensitive cells to the 

 action of radium and x-rays. The senior writer has indicated 

 in his previous publications that this action differs specifically 

 for the various types of the white blood cells. This "selective" 

 biological action of the rays goes even beyond the apparent struc- 

 tural differences of the cells. The rays for instance destroy 

 rapidly the lymphocytes of lymphatic leukemia, while they have 

 a comparatively slight effect on the lymphocytes in conditions of 

 inflammatory leucocytosis. As a general rule the result of the 

 action of radium and x-rays on the normal blood consists in the 

 diminution of the number of lymphocytes and a relative increase 

 in the number of the polymorphonuclear leucocytes. The other 

 types of leucocytes usually remain unaffected. 



