BY R. GREIG SMITH. 125 



Relation to media, temperature and oxygen. — The organism 

 grows quickly in the usual culture media at 20° as well as at 37°. 

 In the absence of air, the growth is very scanty indeed. 



Gelatine plate. — The colonies appear at first as white circular 

 points, which develop into circular colonies. The medium slowly 

 liquefies, forming a shallow, saucer-like depression, in which the 

 colony assumes a more or less zonal or annular appearance. 

 There may be a white centre, around which are arranged circles 

 or zones of varying intensity of white, or the centre may be clear, 

 the margin clear, and midway between centre and margin a 

 broad ring, which may appear homogeneous or striped with radial 

 bands. As liquefaction proceeds the growth gathers towards the 

 centre and the margin, when an appearance is presented like that 

 figured in Lehmann and Neumann's Diagnostik, i. 37, iv. This 

 stage is reached in about 4 days, at 22° C. 



When examined with a 60-fold magnification, the colonies near 

 the surface and deep in the medium are circular, granular and 

 brownish-black in colour, with a rough margin as if beset with 

 short hairs. In thickly sown plates the deep colonies are irregular 

 and generally studded with opaque root-like fibres. The colonies 

 absolutely on the surface spread at first irregularly like a frag- 

 ment of twisted or crumpled paper. The rosette-like colony then 

 sends out straight and sinuous granular processes, which are 

 visible as long as liquefaction has not proceeded very far. At 

 the later stages, when the colony has assumed the annular 

 appearance, the structure is seen to consist of tufts of short 

 interlacing threads. 



Gelatine stab. — At first there is an uncharacteristic white fili- 

 form growth along the track made by the inoculating needle. 

 The growth widens a little more at the surface than in the depth; 

 an air-bubble then appears at the top of the canal. Liquefaction 

 proceeds in the upper layers of the gelatine, producing a funicular 

 or napiform liquefied space, and at the same time a white film 

 covers the surface of the solid or liquefied gelatine. With a 

 napiform liquefaction the surface film remains indented round the 

 point of inoculation. As the liquefaction proceeds downwards 

 the original white cord- like growth may persist more or less, or it 



