SYSTEMATIC DESCRIPTION OF SPECIES. IOI 



its movements. Goadby, however, describes spiro- 

 chsetes in the mouth, apparently Sp. buccalis, as having 

 a sluggish oscillating movement. It has terminal peri- 

 plastic appendages, and Hoffmann states that it has 

 an undulating membrane ; this is doubtful. Division 

 is said to be longitudinal. 



SPIROCH^ETA DENTIUM. 



(Koch, 1877.) 



This small spiral organism is from 4 to lo/t long, and 

 exhibits well-marked regular curls (Figs. 76, 77, 78). 

 Its breadth is about /i. It very closely resembles Sp. 

 pallida in general appearance, but is said to be rather 

 thicker, usually shorter, and to have rather less sharply- 

 wound curls (Muhlens and Hartmann) . It is uncertain 



FIG. 77. FIG. 78. 



FIG. 77. Spirochaeta dentium. X 1500. (Hoffmann and 

 Prowazek.) 



FIG. 78. Spirochaeta dentium. Culture. (Muhlens.) 



whether these organisms have any pathogenic influence ; 

 they are found chiefly in dirty mouths, in the tartar 

 on teeth, and in the discharges of pyorrhoea ; and Miller 

 found tangles of them in a dental abscess, of which he 

 thought that they were the cause. 



These organisms may perhaps be the same as Loewen- 

 thal's Sp. microgyrata (see below). 



An intermediate form, between Sp. buccalis and Sp. 

 dentium is also described (Sp. media (Prowazek); (?) 

 Sp. denticola, Arndt). Spirillar forms with lateral 

 flagella (Spirillum sputigenum) also occur (Fig. 75). 



