192 



Scientific Proceedings (108). 



is 1-3,000; and for para B 1-300. The third series immunized 

 with para B shows its highest lytic dilution with a heterologous 

 strain, typhoid (1-950); while for para A and para B the corre- 

 sponding dilutions are 1-380 and 1-350 respectively. 



The fourth series of rabbits was immunized with combined 

 triple vaccine, and the degree of immunity reached for each organ- 

 ism (as measured by the highest lytic dilution) would appear to 

 be lower than the degree of immunity obtained for the same or- 

 ganism by inoculation with the single strain vaccine. This 

 result was not wholly anticipated, from the previous work of 

 Castellani 1 and also of Davison. 2 The latter in a series of very 

 completely worked out experiments with agglutinins, reports that 

 the combined vaccine when injected, gives for each organism as 

 good and usually a greater immunity response than if it had been 

 injected alone. Davison, and likewise Bull 3 have also observed 

 some tendency in respect to the heterologous strains to lead to an 

 added formation of the specific agglutinin, a phenomenon some- 

 what comparable to that of "summation" in muscle contraction. 

 Our results with bacteriolysins, in a small series of animals, if 

 confirmed, would appear to differ from Davison's observations 

 with agglutinins. Further experimentation along these lines is 

 desirable, and it is our hope to amplify our own work with improved 

 methods. 



102 (1562) 



Studies on intestinal implantation of Bacillus acidophilus. 

 By Harry A. Cheplin and Leo F. Rettger. 



[From Yale University, New Haven, Conn.] 



B. acidophilus (Moro) is a common inhabitant of the intestinal 

 tract of the albino rat and of man. Ordinarily it is present in 

 very small numbers, however, and often may escape detection. 



Diet exerts a profound influence on the character of the 

 intestinal flora. Lactose and dextrin, when fed in sufficient 

 amounts, bring about a marked transformation in bacterial types. 



1 Ibid, and Centralbl. Bakt., 1909, Ab. I, 52, p. 92. 



4 Davison, W. C, Arch, of Inter. Medicine, 1918, XXI, 437. 



» Bull, C. G., Jour. Exp. Med., 1916, XXIII, 419. 



