CHAPTER XVIII 



THE SPIRILLUM GROUP 

 Members — 



Spirillum cholerae asiaticae. 



Sp. of Finkler and Prior. 



Sp. Metchnikovi. 



Sp. tyrogenum. 



And a number of spirilla indigenous to water. 



Great caution must be exercised in manipulating the 

 spirillum of asiatic cholera. 



Inoculate agar-slants from stock-cultures of Sp. 

 cholerae asiaticae, Sp. of Finkler and Prior, and Sp. 

 Metchnikovi. 



1. Routine study. — In addition to the usual media, 

 inoculate an extra tube of Dunham's peptone-solution 

 from each organism. Observe carefully from day to day 

 the action of these three organisms on gelatin, and com- 

 pare the results by tabulation. Observe the formation 

 of coccoid involution forms on agar after 3 days. Also 

 make plates in gelatin, observe the colonies from day 

 to day, and compare. 



2. Special study A. — Test for the nitroso-indol or 

 cholera-red reaction. (See test for indol, p. 83.) Make 

 two tests, using one of the cultures in Dunham's solution 

 after 24 hours, the other after 6 days. Compare the 

 results of these tvi^o tests. 



3. Special study B. — Stain for flagella by LoefHer's 

 method (see p. 86). 



4. Special study C. — Schottelius' enriching method. 



