250 THE UNIVERSITY SCIENCE BULLETIN. 



Dr. Victor C. Vaughn, ^^ citing the collected studies of Eisenberg 

 on "Mutation in Bacteria," gives a splendid brief discussion of 

 the subject. In conclusion he says: "Evidence of mutation in 

 bacteria might be multiplied many times. It is shown in changes 

 of form, in capsule formation, in production of spores, in alteration 

 of virulence, etc., but I think that I have collected enough data to 

 conclusively show that in bacteria acquired characters are in part 

 at least inheritable." 



The tendency toward pleomorphism was quite persistent for 

 the streptococci reported upon in this paper. After seven months 

 cultivation there was a tendency toward uniform chain formation, 

 but decided involution forms would occur. The variation in 

 morphology of streptococci in liquid media, such as mannite broth, 

 saccharose broth, etc., reported by Jean Broadhurst^* was much 

 more temporary but quite interesting. She says: "The morphol- 

 ogy of the individual cell may be likewise affected. In media not 

 utilized, some of the chains are usually of full or increased length, 

 and there is usually a small proportion of swollen organisms 

 (rounded and elliptical) either in short chains or interposed here 

 and there in chains composed mainly of normal organisms. When 

 the media are utilized, there is, besides this swelling, a distinct 

 tendency to abnormal shapes . . Often, however, more 



varied forms are seen — organisms which may be actually pear- 

 shaped, club-shaped or obtusely diamond shaped. These changes 

 are most marked in mannite, though they may occur in other 



media A normal appearance is effected at once by 



transplanting to plain broth." Jean Broadhurst also made an- 

 other interesting observation, which was that a strain of strepto- 

 coccus producing no change in litmus milk acquired the ability of 

 producing acid and of coagulating the milk by being put into a 

 capsule and passed through the intestinal tract of a dog. 



Repeated attempts have been made without success to control 

 the pleomorphism of these organisms. In view of the observation 

 that involution forms appeared quite frequently upon partly 

 desiccated solid media, it was thought that perhaps differences 

 in osmotic pressures might be responsible for the variations. 

 Accordingly bouillon containing different concentrations of dex- 

 trose were tried, as were also different concentrations of NaCl, 

 but the involution could not be controlled or increased in slightly 

 involuting strains. Then culture media containing different con- 

 centrations of HCl and NaOH were tried, with unsatisfactory 

 results. Since in the first organism isolated it was possible to get 



