BY R. GREIG SMITH. 119 



carbol-violet, and show unstained portions which are not constant 

 in location, being generally between the middle and end of the 

 cell. In the Y-shaped forms the compound nature may be dis- 

 cerned, and it is seen to consist of three organisms enclosed in a 

 branching capsule or tube. The y-forms are made up of a rod 

 and one or two smaller cells; the latter may spring from the end 

 of the rod perpendicular to the plane of the film, and become 

 bent over at right angles, or nearly so, during the process 

 of drying the coverglass. The various forms are most numerous 

 in cultures upon solid media containing potassium phosphate. 

 Sach a medium can be prepared by adding 10% gelatine or 2% 

 agar to the peptone-glucose solution recommended in a former 

 paper.* In a two days' culture upon this gelatine medium all 

 the variety of forms can been seen. The plate which accompanies 

 this paper was prepared from a film of such a culture; the cells 

 were stained with carbol-violet. 



The organisms as observed in the hanging drop are motile, 

 spinning round and darting about the microscopic field. The 

 flagella are generally two in number and located at one end of the 

 simple cell, but they also occur singly at one end, and sometimes 

 at both ends, of the organism. 



The optimum temperature is 28-30° C, and although it grows 

 at 37° on solid media the growth is restricted. In opposition to 

 Sewerin I find that there is practically no growth in nutrient or 

 nitrate bouillon at 37°. Under anaerobic conditions, it forms a 

 scanty growth on agar. On ordinary acid potato the growth is 

 luxuriant, moist glistening, creamy- white and spreading ; the 

 colour ultimately becomes brownish-yellow. Sewerinf in his first 

 paper said no growth occurred on potato, and in his second that 

 there was formed a narrow, flat, yellow-brown, dry stroke. The 

 other cultural characteristics agree ^with Sewerin's description. 

 It may be well, however, to point out that there are many 

 similarities in the growth of this organism with Bact. Hartlehii. 



* These Proceedings, 1899, Part 4, p. 661. 

 t Sewerin, Centralblatt flir Bakt. ii. Abt. i., 162; iii., 510. 



