344 



Dr. D. Ellis. 



[May 17, 



is necessary to work at such high current-densities that external cooling is 

 required to control the temperature of the cell. 



The preliminary investigation of the conductivity of hacteria and their 

 behaviour in ultra-violet light was made in the Thompson-Yates Laboratories 

 of the University of Liverpool in the summer of 1901. The author is in 

 particular indebted to the late Sir Eubert Boyce for instruction and encour- 

 agement in the earlier work, and to Professor Hutchens, of the University of 

 Durham College of Medicine, in the later stages. 



An Investigation into the Life-history of Cladothrix dichotoma 

 (Co/in). 



By David Ellis, Ph.D., D.Sc, F.E.S.E. 



(Communicated by H. W. T. Wager, F.R.S. Received February 27, — In revised 

 form May 17— Read June 20, 1912.) 



[Plate 8.] 



The name Cladothrix dichotoma was first applied to this organism by Cohn 

 in 1873. In 1875 he also founded the genus Streptothrix to include an organism 

 (S. Foerstcri) which differed from Cladothrix mainly in the possession of a 

 mycelial habit. In 1887 the genus Actinomyces was also instituted by the 

 same writer, to include the newly discovered A. bovis. Whatever may be the 

 value of the distinction made by Cohn between Streptothrix and Actinomyces, 

 there is no doubt whatever about the clearness of the line of separation which 

 he set up between these genera and Cladothrix. Unfortunately, later writers 

 have used the term Cladothrix to indicate not only the only organism belong- 

 ing to the group, but also species belonging to Streptothrix. As examples may 

 be mentioned the organism described by Cienkowski (3) in 1877, which he 

 describes as having a branched mycelial habit. The same mistake was made 

 by Winter (21) in 1884. Influenced, doubtless, by these descriptions, Mace" (14) 

 in 1884 denied the separate identity of Streptothrix and Cladothrix. In his 

 work he describes the characteristics of Cladothrix, and gives, under this name, 

 precisely those denned by Cohn as belonging to the genus Streptothrix. The 

 confusion by this time had become fixed, and we find the same mistake in 

 later writers. Thus Giinther and Rullmann (10), in 1896, describe as 

 Cladothrix odorifera what is obviously a Streptothrix. Again, Acosta and 



