I9I5] A. F. Blakeslce and Ross Aiken G ortner 49 



number of spores recovered from its blood. After about lo hours, 

 viable spores gradually disappear from the blood stream and are no 

 longer found after 43 hours. It is of significance that they disap- 

 pear from the blood of the rabbits which had been previously treated 

 with spores, no sooner than from the controls. No cytolysins, 

 therefore, or other antibodies capable of destroying the spores have 

 been developed in response to previous injections. 



Each of the treated rabbits received an enormous number of 

 spores during the period of injections and must have disposed of 

 them in some way — how, has not been determined. Postmortems 

 on animals 5 and 55 failed to show abnormal conditions of the 

 viscera. Further, the lungs, liver, spieen and kidneys were pre- 

 served and later examined microscopically but failed to give evi- 

 dence of any local accumulation of spores. The spores have hyaline 

 walls and may not greatly differ from blood corpuscles in size or in 

 appearance, when either of these are for any reason distorted. It 

 seemed desirable, therefore, to postpone search after the fate of the 

 injected spores until a form might be used with walls that could be 

 easily identified. 



A series of experiments was performed in vitro with the sera 



of the treated rabbits. Animals 5 and 55 were bled Aug. 22, nine 



days after their last injection. On Aug. 24, the action of their sera 



and that of a control ? rabbit No. 80 was tested on c? and 2 spores. 



The number of spores was roughly determined with a hemacytom- 



eter. One cc. of the spore mixture containing in the neighborhood 



of 12,000,000 spores was added to 0.5 cc. of the different sera and, 



together with controls in salt Solution alone, the tubes were placed 



in the incubatirig oven. It is not impossible that rather more 6 



than 2 spores were added to each tube and this fact would explain 



the uniformly high counts for all tests of c^ spores in this series. 



The results are shown in Table 2 and merely confirm the facts 



brought out in Table i— /. e., that the sera of the treated rabbits 



developed no antibodies for the destruction of spores. 



Although no cytolysins were developed, there was found evl- 

 dence of the formation of agglutinins in the blood of the treated 

 animals. On Aug. 26, about 6,000,000 J" and ? spores, respectively, 

 were added in 0.9 percent salt Solution to various dilutions of the 

 sera of the same rabbits (Nos. 5, 55 and 80), and controls were 



