in.] CHOLERAIC COMMA-BACILLI. 55 



resting-stage of the cholera-bacilli, analogous to the spore- 

 formation of other bacilli, but I have, just as in my former 

 investigations on this point, obtained only negative results. 

 All the statements as yet made by other observers on the 

 resting-forms and spore-formation depend evidently on 

 errors." (Compare also Koch's experiments mentioned on 

 pp. 1 6 and 17.) 



The complex process of spore-formation of the choleraic 

 spirilla described by Ferran, namely by the formation of a 

 peronospora, has not been confirmed ; and it is difficult to 

 come to any other conclusion as regards them than that 

 Ferran's cultivations were impure, and that accompanying 



FIG. 14. FROM AN ARTIFICIAL CULTIVATION OF CHOLERAIC MUCUS-FLAKES ON 



DAMP LINEN. 

 Comma-b&cilli of the ordinary type. Amongst them are some much thicker containing 



a vacuole. 

 Magnifying power about 700. 



the comma-bacilli there were probably present other forms 

 as an accidental contamination, or that he mistook degener- 

 ative forms for indications of spore-formation. 1 



A curious degenerative change, besides the granular dis- 

 integration already mentioned, is observed in some Agar- 

 agar tubes, consisting in the swelling up of one end of the 

 comma-bacilli, whereby the ordinary comma-bacilli become 

 changed into pear-shaped or club-shaped, straight or more 

 or less curved and twisted, corpuscles. But these ultimately 



1 Carillon, Ceci and others describe spherical enlargements and 

 vacuolation as spore- formation in the comma-bacilli. 



