BY OSCAR KATZ, PH.D., M.A. 919 



Bacillus C. 



Microscopical Characters. Delicate, slender rods, of from -00 15 

 — -0035 mm. in length, and about -0004 mm. in width ; with 

 somewhat acutely rounded ends ; occur usually in threads or fila- 

 ments, made up of a great number of individual rods. 



On gelatine-plates. Growing superficially it forms, at firsk, 

 very thin, irregularly shaped, opalescent films, which, under a low 

 magnifying power, show a mosaic-like arrangement of their 

 contents. Later on, with the moderately quickly advancing 

 growth of the colonies, liquefaction of the gelatine sets in, and at 

 the bottom of the watch-glass-like excavation in the latter, 

 now a liquid mass, there is seen a net- work of ochre-yellow, 

 rather thick and short strings which, taken as a whole are 

 longitudinal or circular in shape (PL X, fig. 2, c). These 

 colonies spread themselves peripherally more and more, as more or 

 less elongated threads, which are combined in more or less wide 

 and elongated bundles, these being themselves in communication 

 with one another in the most various ways. 



In the interior of the gelatine the colonies have, from the very 

 beginning, a yellowish colour. 



When in quite a young stage of development (of from -02-* 2 

 mm. diam.) the colonies of this bacillus seldom represent, as a 

 whole, a circular shape (optical section), but they are mostly 

 irregularly circumscribed, with their contents slightly emarginate 

 and partly provided with offshoots, often of the most curious and 

 fantastic kind, in so far as they resemble root-fibres, legs of mites 

 and insects, or the like. Contents of these colonies granular, 

 translucent with a yellowish tint. 



In nutrient gelatine in a test-tube this form grows in the shape 

 of an inverted, elongated cone which, if looked at in transmitted 

 light, offers a beautiful aspect inasmuch as a central axis represent- 

 ing the course of the inoculating platinum-wire, appears to be beset, 

 all round, with an almost invisible, extremely fine and delicate, 

 cotton-wool-like mass, of a cloudy appearance. The growth 

 here proceeds but slowly. At the surface of the gelatine the 



