314 



KAJSr-ICHIRO MORISHIMA 



Cohen S emulsion 



Cohen B emulsion • 



0.9 



0.8 



0.6 



0.3 



+ 



+ 



+ 



This experiment shows that the Cohen S strain absorbed either 

 no agglutinin at all or so little that it could not be demonstrated 

 by strong solutions of sodium chloride. 



We have now shown that the typhoid bacillus, which loses 

 agglutinability after prolonged cultivation on immune serum, 

 becomes inagglutinable because of its failure to absorb agglutinin. 

 It was next desirable to determine, if possible, whether this 

 inability to absorb antibody was due to an ectoplasmic insulation 

 substance identical with or analogous to a capsule, since capsule 

 formation in other bacteria has been shown to protect against 

 serum effects. In spite of repeated attempts we never succeeded 

 in demonstrating a capsule in our serum strains by staining 

 methods. However, Bail and others have suggested that such 

 capsular materials might be present in bacteria without showing 

 demonstrable morphological change, except perhaps in the form 

 of increased size of the bacterial cell as a whole. For this reason 

 it seemed advisable to investigate this question by the method 

 of Forges, who rendered the heavily capsulated and inagglutinable 

 Friendlander bacilli agglutinable by dissolving off the capsule 

 with weak acid and moderate heat. 



If it be true that the inagglutinability of Cohen S is due to 

 the formation of a capsule or something similar, then hydrolysis 

 of protein of that capsule by Forges' (1905a, 1905b) method 

 should restore the agglutinability. With this idea in mind, we 

 tried the next experiment, using Rawling's serum, and carrying 

 out the method of Forges exactly as described by him. The 

 following tubes were prepared : 



I. 3 cc. of each bacterial suspension plus 2 cc. of salt solution. 



II. 3 cc. of each bacterial suspension plus 1 cc. of N/4 HCl 

 plus 1 cc. of salt solution. 



