MICROSPIRA SCHUYLKILL1ENSIS. 507 



is a little shorter and thicker than the microspira 

 comma, though this feature is quite variable. It is 

 actively motile, having a single polar flagellum. It 

 does not form spores. It stains with the ordinary ani- 

 line stains, but is negative to Gram's method. 



COLONIES ON GELATIN. The colonies are sharply 

 defined, distinctly granular, and have usually fine 

 irregular markings, as if they were creased or folded. 

 Sometimes they present indistinct concentric mark- 

 ings. As growth progresses these markings be- 

 come more and more distinct and finally give to 

 the colony a decidedly lobulated or mulberry-like 

 appearance. 



After about the third or fourth day, when liquefac- 

 tion is actively in progress, the majority of the colonies 

 lose their characteristic appearance. They are seen as 

 irregular, ragged, granular masses lying in the centre 

 of pits of liquefied gelatin. 



GELATIN STAB CULTURES. In stab cultures in gel- 

 atin the appearance of the growth is essentially that of 

 microspira comma, though at times it is a little more 

 rapid in its progress. 



GROWTH ON AGAR-AGAR. On meat-infusion agar- 

 agar, neutral or slightly alkaline to phenolphthalein, 

 growth is very rapid at the body temperature. The 

 general character of the growth corresponds to that of 

 microspira comma. 



BLOOD SERUM. The growth on blood serum, after 

 twenty-four hours at body temperature appears as a line 

 of depression, which increases as a track of liquefaction, 

 and later results in the more or less complete liquefac- 

 tion of the medium. 



BOUILLON. Bouillon becomes uniformly clouded in 



