230 MANUAL OF BACTERIOLOGY. 



thiothrix) contain sulphur granules. Many of them occur 

 in water. There are forms among them which are found 

 attached to some object by one end of the filament (thio- 

 thrix). Some of them (actinomyces or streptothrix) have 

 branching filaments, which are rarely seen among the lower 

 bacteria (see page 119). Often one end of the filament be- 

 comes specialized for the purposes of reproduction. The 

 fungus of actinomycosis is the best known of this group. 

 There are many other members, however, both pathogenic 

 and non-pathogenic. Most of them require still further 

 study. The tubercle bacillus and other acid-proof bacilli 

 which resemble it, have some points of resemblance with 

 actinomyces (see B. tuberculosis, Part IV.). 



Leptothrix buccalis. Found in the mouth cavity. This 

 name has been applied to large, twisted, thread-like organ- 

 isms, in which segments can be demonstrated with diffi- 

 culty or not at all. Apparently, different organisms have 

 been described under this name. Vignal claims to have 

 cultivated a leptothrix buccalis. Miller recognizes two 

 principal species, neither of which could be cultivated, 

 leptothrix innominata, which shows no transverse divisions, 

 and which is stained faintly yellow by iodine; and bacillus 

 buccalis maximus, in which the transverse divisions are 

 distinct, and which is stained brownish-violet by iodine. 

 Miller's leptothrix maxima buccalis is similar to the last 

 except in lacking the iodine reaction. 



A variety of leptothrix, or a nearly related organism, ap- 

 pears to be the most frequent cause of the form of gangren- 

 ous inflammation of the mouth and genitals called noma. 

 It stains faintly by Gram's method. It does not grow on 

 ordinary media. 1 Another organism of this group has been 



1 Blumer and MacFarlane, American Journal Medical Sciences, 

 November, 1901. 



