THE CLADOTHRICES 229 



The reaction of Grape and Milk Sugar Media is not changed, and no 

 gas is formed. 



Indol is not formed. 

 Non-pathogenic. 



THE CLADOTHRICES. 



These organisms are found in water, and consist of colourless 

 bacteria, which do not contain sulphur grains ; arranged in threads. 

 The principal characteristic of this group is thejalse branching of the 

 threads or pseudo-ramification. Three forms of Gladothrix are well 

 known. 



CLADOTHRIX DICHOTOMA (R COHN). 



Found in both standing and running waters, which are more or less 

 rich in organic substances. It is frequently associated with the 

 Beggiatoa. It occurs in stationary tufts, 1 to 3 mm. high, and free in 

 floating flakes. From the point of the Cladothrix threads individual 

 elements (Rodgonidia) become detached and float round free for a time, 

 then become stationary, and develop into fresh threads. The individual 

 threads possess a distinct sheath. Artificial cultivation is very difficult. 

 In solutions of extract of meat a thin film forms, which extends over the 

 surface of the media and the walls of the tube. In meat extract gelatine, 

 ramifying colonies, causing very slight liquefaction of the medium, develop. 

 (For Photomicrograph of Cladothrix cultivated from drinking water, see 

 Fig. 84.) 



CLADOTHRIX INTRICATA (RUSSELL). 



Found in sea slime in the Gulf of Naples. It is always free, and 

 develops no sheath. It forms no tree-like ramifications, but an interlaced 

 mass of threads. In certain threads the pseudo-ramification occurring 

 in C. dichotoma takes place. The fresh threads are homogeneous, and 

 when stained the large bacilli of which they are formed become distinctly 

 visible. When free those bacilli become actively motile, and develop 

 spores which are not thicker than the threads. It is easily cultivated 

 artificially. 



On Gelatine Plates, mould-like, quickly liquefying colonies develop, 

 which under a low power appear to consist of a tangled mass of threads. 



In Gelatine Stab Cultures radiations are given off from the growth, 

 which become shorter towards the bottom of the stab. 



On Agar, a whitish coating develops, from which projections penetrate 

 the medium. 



