February 9, 1906.] 



SCIENCE. 



215 



tive ; 0.00003 of a gram will indicate 0.001 

 of a gram of hydrochloric acid. 



The addition of the indicator to the or- 

 dinary culture media does not influence 

 the growth of bacteria. The delicate 

 changes in reaction are best obtained by 

 Dunham's peptone solution, containing six 

 per cent, glycerin and two per cent, of the 

 acid fuchsin. In the ordinary culture 

 media, such as beef peptone bouillon and 

 beef peptone gelatin and agar, the resvilts 

 are not delicate or constant. Their differ- 

 ences are probably due to the changes in 

 the reaction in sterilization. 



The dysentery groiip shows quite a range 

 in acid production, as to both amount and 

 the time it occurs: 



B. dysenteries Shiga, acid slight, four to five 

 days, neutral after three weeks. 



B. dysenterice Kruse, acid slight, four to six 

 days. 



B. dysenterice Flexner, acid slight, four to six 

 days. 



B. dysenterim New Haven, considerable, four to 

 six days. 



B. " Y " Hiss and Russell, none, alkaline in ten 

 days. 

 Paracolon Group. 



B. paracolon Kurth, none, alkaline in fourteen 

 days. 



B. paracolon Strong, none, alkaline in fourteen 

 days. 



B. paracolon Badash, none, alkaline in fourteen 

 days. 



B. paracolon Gwynn, considerable in four days. 



B. paracolon Miller, considerable in four days. 



B. paracolon Buxton, considerable in four days. 



B. paracolon Gushing, considerable in four days. 

 Hog Cholera Group. 



B. cholera suis, none, alkaline in ten days. 



B. icteroides Sanarelli, considerable in four 

 days. 



The study and growth of the above or- 

 ganisms in media containing glycerin, and 

 the acid fuchsin indicator, shows that they, 

 so far as acid production is concerned, 

 arrange themselves in groups, the Bacil- 

 lus 'T' of Hiss and Russell, B. paracolon 

 Strong and Kurth, forming a distinct^ 

 Sroup.,., ,, ,H -.o. 



Agglutination and Biological Relationship 

 in the Prodigiosus Group: Mary Hef- 

 FERAN, University of Chicago. 

 A series of organisms with cultural char- 

 acteristics like those of B. prodigiosus were 

 examined for agglutinative activity. This 

 series had been under the writer's observa- 

 tion for five years and the biological rela- 

 tionship of the twenty-two different mem- 

 bers of the group had been fairly well 

 determined.^ Agglutination tests showed: 



1. A high degree of interaction among 

 those members of the group which were 

 classed together by the sugar fermentation 

 test. 



2. Identity of reaction of races known to 

 have been derived from the same culture 

 eight or ten years previously, and kept in 

 different laboratories. 



3. Agglutinative' reaction among those 

 members of the group which tend to lose 

 the power of pigment production, including 

 one race which produces only a soluble red 

 pigment. No reaction was obtained in this 

 case with B. fluorescens liquefaciens or B. 

 lactis erythrogenes. 



4. Much confusion and inequality of in- 

 teraction among other members of the 

 group closely related biologically. 



The difference between agglutinogenic 

 power and agglutinability was clearly due, 

 in some cases, to a viscid capsular condition 

 of the bacilli. On the other hand, readily 

 agglutinable cultures did not possess cor- 

 respondingly high agglutinogenic power. 



Experiments made to determine the op- 

 timum temperature for the agglutination 

 process showed that better results were 

 obtained at either 0° or 55° C. than at 

 room temperature or at 37° C. The action 

 of convection currents in the tubes of 

 serum dilution and bacilli at high and low 

 temperatures was suggested as an explana- 

 tion. 



^Centralbl. f. Bakt., 1904, 11, pp. 311, 397, 456, 



