SPIRILLUM CHOLERA ASIATICS. 



425 



owe their origin, is only observed in cultivations which 

 are kept moderately warm. It is only relatively seldom 

 that these spirilla can be well demonstrated in stained 



Vi jT" i I'M ?'*'/ 



mm 

 ,lis 



Fig. 117. (After Koch.) Cover glass 

 preparation. 



Cholera dejecta on moist linen (two 

 days old). Marked multiplication 

 of the comma bacilli among which are 

 S-shaped forms (a) X 600. 



Fig. 118. (After Koch. ) Cover glass 

 preparation from the contents of the 

 intestine in a case of cholera. 



Nuclei of the dead epithelial cells (a). 

 Semicircular comma bacillus (b). 

 Very characteristic arrangement of the 

 comma bacillus (c) X 600. 



cover glass preparations ; as a rule the turns appear 

 more or less opened out, so that we find almost straight 

 threads ; or the threads become torn, and we only 

 obtain short fragments. Hence the morphological 

 characters of the comma bacilli are best studied in 

 drop cultivations ; in order to prepare these cultiva- 

 tions a drop of alkaline meat infusion (for the method, 

 see the last chapter) is placed on a cover glass infected 

 with a minute quantity of a cultivation of comma bacilli, 

 and then so fixed on a hollow slide by the aid of vaseline 

 that the drop hangs into the depression in the slide. 

 The preparation is now kept at from 25 to 30 C., and 

 the further development of the spirilla is watched from 

 time to time by means of a high power (oil immersion). 



