DESCRIPTION OF SPECIES. 



541 



Bacterium photometricum(En- 



gelmann). Rods slightly reddish in 

 colour ; motile. 



The movements are stated to 

 depend on light. 



Bacterium synxanthum (Ehren- 

 berg ; Bacterium xanthinum ; Bac- 

 terium of yellow milk). Cocci '7 to 

 1 /z in length, and rod-forms. 

 They produce a yellow colour in 

 boiled milk, which at first becomes 

 acid, and then strongly alkaline. 

 They also occur on boiled potatoes, 

 carrots, etc., where they form small 

 lemon-yellow masses. 



The colouring-matter is soluble 

 in water, insoluble in ether and 

 alcohol, unchanged by alkalies, de- 

 colorised by acids. It is similar 

 to yellow aniline colours, both 

 spectroscopically and in ordinary 

 reactions. 



Bacterium termo (Vignal). 

 Rods 1*5 to 2 p. in length, *5 to '7 p. 

 in width. 



Colonies white, surrounded by 

 liquefied gelatine. 



The bacilli inoculated in the 

 depth of gelatine produce a funnel- 

 shaped area of liquefaction ; later, 

 the jelly is completely liquefied and 

 coloured green. Cultures have a 

 strong putrefactive odour. 



In broth they form a white 

 deposit and colour the medium 

 green. 



They were isolated from human 

 saliva. 



Bacterium tholoeideum (Gess- 

 ner). Rods similar to Bacillus 

 lactis aerogenes. 



Pathogenic in small animals. 



They were isolated from healthy 

 human evacuations. 



Bacterium ureas (Cohn). Cocci 

 1*25 to 2 /z in diam., singly or in 

 chains, and rods. The rods split 

 up by division into chains of cocci, 

 which after a time are set free. The 

 cocci increase further by subdivi- 

 sion, and a jelly-like membrane 

 develops around them. Masses of 

 cocci exist in the form of irregular 

 or roundish lumps. They are 

 aerobic. 



Cultivations, after twenty-four 

 hours, consist exclusively of rods ; 



after forty-eight hours, of cocci 

 chains ; and in fourteen days, of 

 zoogloea ; the cocci transplanted 

 into fresh nourishing solution again 

 grow into rods. These observations 

 point to the existence of a pleo- 

 morphic species, Bacterium urece ; 

 and the former nomenclature, Micro- 

 coccus urece, must be regarded as 

 untenable. 



In urine they set up ammoniacal 

 fermentation, converting urea into 

 carbonate of ammonia. Rods, 2 p. 

 long and 1 /z wide, have been iso- 

 lated from stale urine (Bacillus 

 urese, Leube), which also most 

 energetically cause the ammoniacal 

 fermentation of urine. 



Bacterium ureae (Jaksch). 

 Rods 2 /* in length, 1 /z in width. 



Colonies on gelatine semi-trans- 

 parent. 



Inoculated in the depth of gela- 

 tine the bacilli form a delicate 

 branching growth in the track of 

 the needle. 



They convert urea into carbonate 

 of ammonia, and cultures smell of 

 herring brine. 



They occur in ammoniacal urine. 



Bacterium yiolaceum (Bergon- 

 zini). Rods similar to Bacterium 

 termo, '6 to 1 /z thick, 2 to 3 tt long. 



They occur on white of egg, 

 forming a violet pigment. 



Bacterium Zopfii (Kurth). 

 Cocci, 1 to 1'25 /z in diam. ; rods 

 and threads. Cultivated in a streak 

 on nutrient gelatine spread out on 

 a glass slide, a peculiar develop- 

 ment takes place. In twenty-four 

 hours after inoculation threads 

 have developed ; in forty-eight 

 hours windings of the threads 

 are observed, and in six days the 

 threads have broken up into cocci. 

 They were observed in the intestine 

 of fowls, especially in the contents 

 of the vermiform appendix. In- 

 oculation of rabbits was followed 

 by negative results. Identical with 

 Bacillus figurans (Crookshank). 



Beggiatoa alba (Vauch). Cocci,, 

 rods, spirals and threads (Fig. 215). 

 The threads are indistinctly articu- 

 lated, actively oscillating, and colour- 

 less ; their protoplasm contains 



