SEPARATION OF BACTERIA 97 



(A) Round colonies, edges entire and oleaginous. 

 Surface flat, central portion finely granular. 



(B) Round colonies, edges oleaginous and un- 

 dulate. Surface effused, form amoeboid. Colonies 

 show a central growth, brownish in colour, with 

 feathery processes extending into a very clear 

 border. These later developed amoeboid processes 

 which grew rapidly, and sometimes became de- 

 tached from the parent colony. Cultures were 

 made from each type, and stained films showed 

 bacilli somewhat similar in appearance. As type 

 B colonies were very scanty and crowded in by 

 type A, it was considered advisable to prepare a 

 further plate from a small portion of the first one. 

 Two types of colonies were again obtained (C and 

 D), which were obviously reproductions of A 

 and B. As the types were very well separated on. 

 this plate, slope cultures were made from them,, 

 and analysed (vide chart). On the fourth day 

 a third type appeared on the plate similar to A, 

 but darker in colour and smaller. A slope culture 

 of this was taken (E) and found to be identical 

 with A, E being only a deep-seated A type. 



In addition to the above principal analyses, 

 several other bacteria have been separated from the 

 impure cultures, viz. : 



B. prodigiosus, three sporing bacilli, namely, JB. 

 megatherium, bacillus of malignant oedema, and a 

 third, a variety of the anthrax group but not yet 

 identified with certainty (possibly B. mesentericus 

 vulgatus}. The amoeba parasite has been obtained in 

 pure culture, and its description will be found in the 

 chart. Later still, a fourth bacillus with a terminal 

 spore, whose identity is not known, was isolated, 

 iv 7 



