122 



C. C. WARDEN, J. T. CONNELL AND L. E. HOLLY 



\dously shown that the serums of rabbits immunized with Mega- 

 therium organisms and with toxin contained strong agglutinins 

 and precipitins. The Megatherium antibodies diminish fairly 

 rapidly in the serums of rabbits after having reached their 

 maximum. This fact was shown by repeated experiments upon 

 the antihemolytic power of the serums from both the series of 

 annuals immunized with germ bodies and toxin, and with the 

 artificial antigen, they having been bled two days and again 

 four days after the first drawing. The subsidence in antibody 

 titer was shown to be parallel in the two series. 



TABLE 13 



Shows the hemolytic and toxic power of our strain of B. megatherium 

 Toxin no. 1: Twenty-four hour broth culture (composition given above) centrifu- 

 gated clear at high speed, of which 0.04 cc. hemolyzed 1 cc. of 2 per cent red 

 cell suspension in twenty minutes. 



Toxin no. 2: Six day broth culture, centrifugated clear. 

 of red cell suspension in thirty minutes. 



1 cc. hemolyzed 1 cc. 



GUINEA 

 PIG NUM- 

 BER 



Died in less than 12 hours 

 Died in less than 12 hours 

 Died in less than 12 hours 

 Died in less than 12 hours 



Autopsies showed: Abdomen distended; peritoneum bright red, cavity con- 

 taining hemolyzed blood; small intestines hemorrhagic with hemorrhages into 

 the lumen; lungs slightly injected; bloody fluid in pleural sacs; heart muscle 

 injected; bloody transudate over thighs. 



Guinea-pigs nos. 1 and 2 showed much more intense signs than nos. 3 and 4. 



This experiment indicated that both the hemolytic and toxic 

 powers of twenty-four hour cultures of the strain were greater 

 than those of the six day cultures and that, hemolysin and toxin 

 were probably the same substance. 



