in.] CHOLERAIC COMMA-BACILLI. 43 



circular forms is very conspicuous. Here also some were 

 larger than others. 



I have for a long time searched for an explanation of these 

 forms, and I think I have found it. One cause of their 

 abundant appearance seems to be this : the comma-bacilli, 

 by transverse division, and by remaining joined end to end, 

 occasionally form marked spirals, in which the elements are 

 so much curved that the spiral possesses very close turns ; 

 when such a spiral is broken up into its constituent elements, 

 we obtain semicircular and almost circular commas. That 

 this is so I have ascertained in several instances, by com- 

 paring fresh specimens with dried and stained ones. While 

 in the perfectly fresh specimens in these cases a good many 

 spirals with closely-twisted turns were to be made out, after 

 drying a thin film on the cover-glass, staining and mounting 

 it, spirals were absent, being evidently broken up into the 

 numerous semicircular forms then present. Another mode 

 of the formation of these will be given below. Why there 

 should be numerous close spirals in some cases and not in 

 others I cannot say ; but it seems to me that the solidity and 

 resistance of the medium in which they grow has something 

 to do with it, i.e. where the material in which they grow is 

 and remains solid and owing to the resistance offered to .the 

 dividing comma-bacilli, these are limited in the area of their 

 expansion ; hence those which after continued division re- 

 main joined endways, become pushed more closely together, 

 become more curved, and form spirals of closer turns. 

 This, I am induced to think, is in some cases a true explana- 

 tion ; for not only do these forms abound in the depth of 

 solid nutritive material, such as Agar-agar mixture, which 

 remains solid, or in albumen-mixtures, but also in the solid 

 particles taken from the ileum of typical cholera cases. I do 

 not mean to say that other conditions do not determine the 



