568 



DESCRIPTION OF SPECIES. 



They were isolated from sewage 

 mud. 



Spirillum serpens (MuUer).— 

 Long spirilliform filaments ; often 

 collected in masses. 



They were observed in vegetable 

 infusions and stagnant water. 



Spirillum sputigenum (Lewis). 

 — Curved rods, very similar to the 

 comma-bacilli of Koch ; but many 

 observers having failed in repeated 



Fig. 227. — Comm.4-Bacilli of the 

 Mouth, x 700 (Van Bkmengem). 



attempts to cultivate them, main- 

 tain that they are biologically dis- 

 tinct from those associated with 

 Asiatic cholera. Klein asserts that 

 they can be cultivated in an acid 

 gelatine, and that they are iden- 

 tical with Koch's comma-bacilli in 

 their mode of growth. They 

 occur with other bacteria in saliva 

 and in scrapings from carious 

 teeth. 



Spirillum suis (Smith). — Com- 

 mas and spirilla. 



Colonies in gelatine are circular, 

 granular and brownish, and later 

 appear to be composed of concen- 

 tric rings. The gelatine is not 

 liquefied. 



Broth with 1 per cent, of peptone 

 becomes in a few days clouded. 



On potato they develop a thin 

 yellowish layer. 



The commas are said to be slightly 

 larger than those obtained from 

 Asiatic cholera, and are not 

 pathogenic. 



They were obtained from the 

 large intestine in swine. 



Spirillum tenue.— Very thin 

 threads, with at least IJ, usually 

 2 to 5 spirals. Height of a single 

 screw is 2 to 3 /i, and the length of 

 spiral therefore 4 to 15 /jl. They 

 are very swiftly motile. 



They often occur in dense felted 

 swarms in vegetable infusions. 



Spirillum tyrogenum (Deneke). 

 — Curved rods, slightly smaller 

 than Koch's comma-bacilli, with 

 a great tendency to form long 

 spirillar threads (Fig. 228). 





FiQ. 228. — Denbkk's Comma-Bacilli 

 EEOM Cheese, x 700 (FlUgge). 



Colonies on plate-cultivations 

 are sharply defined and of a 

 greenish-brown colour. After a 

 time they liquefy the gelatine, but 

 the liquefaction is much more 

 marked than in colonies of Koch's 

 commas of the same age, though 

 not so rapid as in the case of the 

 commas of cholera nostras. 



Inoculated in the depth of nu- 

 trient gelatine a turbid liquefaction 

 occurs along the needle track, and 

 on the surface of nutrient agar-agar 

 a yellowish-white layer develops. 



Inoculation of potatoes gives no 

 result. 



Administration of the bacilli by 

 the mouth, in the manner employed 

 for testing the pathogenic effect of 

 Koch's bacilli, produced a fatal 

 result in a few cases ; on the other 

 hand, injection into the duodenum 

 failed entirely. The pathogenic 

 properties may be therefore con- 

 sidered as not yet established. 



They were isolated from old 

 cheese. 



Spirillum undula.— Threads 

 1-1 to 1-4 ^ thick, 9 to 12 ^ long ; 

 spirals 4-5 fi high ; each thread has 

 Ij to 3 spirals. They are actively 

 motile, and possess a flagellum at 

 each end. 



They occur in various infusions. 



Spirillum volutans (Ehrenberg). 

 — Threads 1-5 to 2 ^ thick, 25 to 

 30 n long, tapering towards their 



