SPIRILLUM OF RELAPSING FEVER l6l 



ten to twenty ' throws ' in its length. The length varies from 1 6 to 40 /*, 

 and the diameter about J to \ of the comma bacillus. 



Motility. Strongly motile, exhibiting undulations which pass along 

 the threads like a wave. 



Staining Reactions. Somewhat easily stained with fuchsin, 

 alkaline, methylene blue, and Bismarck brown. Some spirilla, owing 

 to their fineness, are only visible with a high power and strong illumina- 

 tion, while, when present in masses in the blood, they are easily seen in 

 both unstained and stained preparations. 



Biological Characters. Outside the body, in blood serum and \ 

 per cent, chloride of sodium solution, they retain their motility for a 

 long time. They have, however, never been cultivated on artificial 

 media. 



Pathogenesis. Monkeys are susceptible when inoculated with 

 human blood containing the spirillum, a typical fever being produced 

 during the height of the same. Great numbers of the spirilla were 

 present in the blood, but were not either before or after. They were 

 also found in the organs of animals killed during the height of the 

 fever. 



The disease could be conveyed from one monkey to another, but 

 only with blood containing spirilla. The typical fever was again pro- 

 duced in a monkey which received a second injection in a few days or 

 weeks after recovery from the first injection (Koch and Carter). 



VIBRIO RUGULA. 



Found in faeces, water, and deposit on the teeth. 



Microscopical Appearances. Slightly bent, finely granular, 

 motile rods, with flagella (see Photomicrograph, Fig. 57) situated at the 

 end of the organism in bundles (Lophotricha). 



Biological Characters. Optimum temperature about 37 C. 



On Gelatine Plates it forms irregular white colonies, the surface 

 colonies consisting of delicate tufts. 



On Agar the growth on the surface of the medium does not possess 

 great vitality, the development in the condensation water being much 

 stronger. 



On Blood Serum, which is not liquefied, the growth is luxuriant. 



Sterile Milk is not altered. 



Indol formation has not been observed. 



It is non-pathogenic. 



L 



