BACTERIOLOGICAL EXAMINATION OF MOUTH AND FAUCES I27 



present, but the spirillum is absent, or present in comparatively 

 small numbers. In either form of the disease the characteristic 

 organism or organisms may be associated with streptococci, 

 staphylococci, etc., and these secondary infections may give 

 rise to grave complications. 



The B. fusiformis, which occurs in both forms of the disease, 

 may be found, in small numbers, as a normal inhabitant of 

 the mouth, and occurs in myriads in the disease. It varies in 

 size, but is on the whole a large bacillus, about as long as the 

 diameter of a red blood-corpuscle, or even longer. Typically it 

 has both ends pointed, giving it the shape of a greatly elongated 

 spindle, but other forms always occur, and may even constitute 

 the majority of the bacilli present. It often contains two or three 

 clear vacuoles, which may not be noticed if the staining is too 

 deep. Both the bacillus and the spirillum are usually actively 

 motile, and it is a good plan to check the results of the examina- 

 tion of the stained films by mounting a fresh wet specimen 

 between slide and cover-glass, and examining it under the oil- 

 immersion lens. 



The B. fusiformis plays a very important part in many in- 

 flammatory and ulcerative conditions in and about the mouth 

 and adjacent cavities, the teeth, etc. For instance, in association 

 with the same spirillum it is present in the pus of pyorrhoea 

 alveolaris. The lesions it causes are all associated with a foetid 

 odour, and the cultures (which are very difficult to obtain) have a 

 similar smell. 



The spirillum occurs only in the ulcero-membranous form, 

 and is present in vast numbers, usually even more plentifully 

 than the bacillus ; a well-prepared specimen is one of the most 

 striking and characteristic objects to be seen in the whole range 

 of bacteriology. It is much longer than the bacillus, very thin, 

 and either wavy and irregular in outline or thrown into definite 

 corkscrew curves. These are better seen in a wet specimen, 

 though here the active motility of the organism often makes it 

 impossible to make out its exact shape. It usually stains badly, 

 and I have missed it in specimens rapidly stained with weak 

 stains : dilute carbol fuchsin stains it very well in a quarter of a 

 minute. In one or two specimens I found the spirilla broken up 

 into chains of very minute granules, so that they resembled long 

 chains of very minute streptococci. In each case it was late in 

 the disease, so that they may have been degeneration forms. 



