X] BACILLI : SPECIAL 187 



the microscope, in stained specimens the growth is made up of 

 threads which consist of rows — generally more than one — of 

 short bacilli ; in many places the bacilli form clusters in the 

 threads (Fig. 59). It does not liquefy gelatine. On the 

 surface of gelatine it forms a filamentous expansion, the 

 filaments growing from the central streak of inoculation like 

 the filaments in the fan of a feather ; the same kind of 



Fig. 5g.— Impression Steclmen of the Filame.\ts of Proteus Zenkeni 

 X 300, 



growth, only not so distinct, is formed by the microbe on 

 Agar ; it grows better at 20° than at 37' C. 



5. Bacillus fluorescem liquescens.~'Y\\\i is a typical water 

 bacillus ; it occurs in most waters — river, lake, pond, well — 

 and in all or most organic substances to which such water had 

 been added. It is a motile, aerobic, non-sjiore-forming 

 bacillus, liquefying gelatine rapidly and producing a fluor- 

 escent greenish or diffuse greenish-blue colouration. Its 



