F. NEGROPHORUS 479 



isolated from the normal flora of the mouth and intestines. Both Varney (1927) 

 and Slanetz and Rettger (1933) divided fusiform bacilli of the normal mouth into 

 four types, I to IV, on the basis of morphological and serological characteristics, 

 but the divisions did not coincide. Agglutination tests revealed a high degree 

 of strain-specificity, and a lesser degree of group-specificity. Weiss and Mercado 

 (1938) extracted immunologically type-specific protein-like substances from 

 organisms of Slanetz and Rettger's Types I, II and III, and also found some evidence 

 of a group-specific carbohydrate in the organisms. Spaulding and Rettger (1937) 

 later divided 84 strains of " fusobacteria " from many sources into two groups. 

 Group I containing their previously described Types I, II and some of Type III, 

 Group II containing the remainder of Type III and Type IV. In a limited cultiiral 

 study of 193 human mouth strains, Peschand Schmitz (1936) distinguished 6 types, 

 but concluded that these were varieties of a single Bacterium fusiforme. Hine 

 and Berry (1937) studied 104 mouth strains, dividing them into three species, 

 F. nucleatus, F. polymorphus and F. dentium. The first two corresponded only 

 very approximately to Spaulding and Rettger's Group I, consisting of short or 

 long fusiform rods of limited saccharolytic activity, and F. dentium to Group II, 

 consisting of long, relatively thick fusiform rods with marked saccharolytic 

 activity. 



Besides these fusiform bacteria of the mouth, there is a large group of Gram- 

 negative non-sporing intestinal bacteria in the contents of the alimentary canal. 

 It is clear from the work of Eggerth and Gagnon (1933), Weiss and Rettger (1937), 

 Misra (1938) and Lewis and Rettger (1940) that these anaerobes are the predominant 

 organisms in the human lower intestine, sometimes outnumbering Bad. coli by 

 one hundredfold or more. They are biochemically and antigenically heterogeneous, 

 though some association between morphological, biochemical and antigenic 

 characters has been noted. 



However, the relation of the normal flora of the alimentary canal to the organism 

 responsible for infective lesions, and particularly to those species which were 

 described in the early years of this century, is not yet clear. The intestinal species 

 in man bear a morphological resemblance to some of the pathogenic species like F. 

 fimdidiformis and certain fusiform bacilli but differ in biochemical reactions (Lewis 

 and Rettger 1940). Until the heterogeneity of both the pathogenic and the 

 " normal " strains has been reduced by further study, speculation on cross-relation- 

 ships within the group is unprofitable. (See Prevot 1938 for a taxonomic review 

 of this difiicult group). 



We append descriptions of some of the named species that have been found 

 in association with infective processes. In the first description we have assumed 

 the substantial identity of F. necrophorus and Bacillus funduliformis, and retained 

 the name F. necrophorus for the two (Dack et al. 1938, Kirchheiner 1940; see also 

 Lemierre, Grumbach and Reilly 1936). 



F. necrophorus. — Synonyms : Schmorrs bacillus, B. diphtherice vitulorum, Streptothrix 

 cuniculi, Actinomyces necrophorus. Bang's necrosis bacillus, B. funduliformis, Bacteroides 

 funduliformis. First observed by Loeffler in 1884 in calf diphtheria. He succeeded in 

 producing necrotic lesions in mice by subcutaneous inoculation of the diphtheritic mem- 

 brane, and in obtaining a primary culture of the organism from mice on calf serum ; but 

 he failed to subculture it. Schmorl in 1891 encountered apparently the same bacillus 

 in a spontaneous epidemic amongst his laboratory rabbits, characterized by spreading 

 necrosis of the lower Up. He inoculated mice with material from the rabbits, and obtained 



