The Microscope. 237 



A NEW COMMA BACILLUS. 



BY DR. W. D. MILLER. 



Considering the great interest which for some months has 

 centered around the so-called comma bacilli, a short description 

 of a new member of this probably very numerous and widely 

 distributed family may not be out of place. 



In the month of May I had occasion to spend a day in Eger- 

 storff, near Hanover, and in the gutter water, as also in the 

 drinking water of this untidy village, I could easily detect, by 

 the use of the microscope, the presence of a comma bacillus. 

 Its pure culture was accomplished on agar-agar without much 

 difficulty ; on this medium it grows rapidly at blood or room 

 temperature, and forms on the surface a thin, bluish, semi- 

 liquid layer, one-half to one mm. thick. On ten per cent, pep- 

 tone-gelatine it grows rapidly at first, but after forty-eight hours 

 its growth seems to cease altogether. On plates, in the second 

 or third dilution, after twenty-four hours' growth, the colonies 

 appear, under one hundred diameters, very irregular, lobular, 

 grayish in color, and traversed by fissures. It differs from all 

 comma bacilli yet discovered, in that it liquefies neither gelatine 

 nor blood-serum. On potato it grows poorly at all tempera- 

 tures. It is somewhat smaller than the comma bacillus which 

 I isolated from the oral secretions, and possesses in a high 

 degree the peculiarity characteristic of the other comma bacilli, 

 of assuming a great variety of shapes and sizes. In growing 

 colonies on agar agar, the cells are tolerably regular, comma or 

 S- shaped ; occasionally one finds spirilla, or long, closely twisted 

 leptothrix. In older cultures, on the other hand, the cells 

 become mostly round, or oval, or lemon-shaped, sometimes 

 much increased in size, while the protoplasm is granularly dif- 

 ferentiated. In gelatine the cells are mostly short and plump, 

 while on potato almost any form may be found. 



The statement of Klein, that comma bacilli occur in the 

 ccecum of healthy guinea-pigs, I have been able to confirm. I 

 did not, however, find them in such numbers as I had expected, 

 after reading his report. Attempts at pure culture did not suc- 

 ceed, so that it would be hazardous in the extreme to make any 

 suppositions as to the identity of these guinea-pig bacilli with 

 any of the known comma bacilli. — Independent Practitioner. 



