24 



Scientific Proceedings (117). 



solution kept at a constant temperature of 38 0 C. When the 

 muscle developed a satisfactory tone "and rhythm, 0.2 c.c. or 0.5 

 c.c. of horse serum was added to the batih at a point which per- 

 mitted uniform diffusion throughout the fluid before coming in 

 contact with the tissue. The uteri of the sensitized and X-rayed 

 animals reacted typically with maximal response just as did the 

 uteri of the sensitized animals not X-rayed. The tracings of the 

 uteri removed at both intervals show no essential differences. 



The information furnished by the data presented we believe 

 to have a direct bearing on the controversial point regarding the 

 locus of antigen-antibody union which results in anaphylactic 

 shock. The results of our experiments indicate that the anaphy- 

 lactic reaction of isolated smooth muscle is not an index of the 

 reaction of the animal as a whole. Also it is indicated that other 

 factors than the reaction of sensitized smooth muscle should be 

 taken into account in the statement of a theory concerning the 

 mechanism of anaphylactic shock. 



We have now in process an investigation in which we are de- 

 termining the relation between the existence of free antigen and 

 the presence of precipitins in the circulation of animals X-rayed 

 and not X-rayed. The results of our experiments to date indicate 

 that free antigen remains in the serum of X-rayed animals for a 

 much longer period than is found in animals not X-rayed. A full 

 report of these results, together with studies on passive anaphyl- 

 axis, will be published later. 



14 (1761) 



Contribution to study of diphtheria toxin. 



By P. J. MOLONEY and L. HANNA (by invitation). 



[From the Research Division, Connaught Antitoxin Laboratories, 

 University of Toronto, Toronto, Canada.] 



The results reported are those of experiments planned tc 

 throw further light on the mechanism of toxin production by 

 B. diphtherice. 



An extended series of test-tube experiments was carried ou 

 in which the Park 8 strain of the diphtheria bacillus was grov 

 in broth and daily counts made of the number of viable organis 



