GENERAL SYSTEMATIC BACTERIOLOGY 231 



hospital gangrene, and in Vincent's angina and many other conditions, as well 

 as in the mouths of healthy persons and in the tartar on teeth. 



It will be noted that the fusiform organism of Vincent's angina is 

 included. Apparently the authors were unaware of the previous desig- 

 nation of Fusiformis (q.v.) as ageneric name for this group. Eight other 

 species are described as belonging to Bacteroides. 



Whether Bacteroides is to be regarded as a valid genus depends on 

 whether Bacteroides fragilis constitutes a generic type which should be 

 placed in a genus other than Fusiformis. 



Bactrella. A generic name proposed by Morren (1830) for an organ- 

 ism apparently to be placed among the bacteria. He states that the 

 genus Vibrio of Bory-de-Saint-Vincent is divided into three subgenera 

 "les lamellinaires, les gordioides et les oxyuroides." The first named of 

 these is elevated to generic rank and named Bactrella. He (p. 354) 

 gives the following descriptions: 



Corpus simplex, elongatum, cylindricum, vel utroque extremo obtusum, vel 

 antice tenuiter, postice e contra admodum attenuatxmi, undique clausum, vel 

 omnio mobile. 



The genus contained Bactrella undula {Vibrio undula Mtill.), Bac- 

 trella bacillus {Vibrio bacillus Miill.), and Bactrella filuni. The descrip- 

 tion of the last species is 



B. corpore longissimo filiformi, cylindrico aequali vel simplici vel bifido (dum 

 procreat) extremis obtuso, rotundato, vel purumper uncinato, praesertim in 

 motibus; libero, recto, extenso rigido immobile vel parum erret languide natanti; 

 aflfixo autem flexuoso, plicatulo, gyris sese contorquenti, apice mobiliore, perraro- 

 quieto, forma paulisper mutabile. Individua libera vel affixa, solitaria aut appro- 

 pinquata, immenso numero corporibus immersis affixa et intermixta. 



This generic name apparently has never been recognized by later 

 writers. It may be regarded as invalid, although possibly the Bactrella 

 bacillus was a Bacillus. Trevisan (1879, p. 137) states: "Resterebbe a 

 vedere,non avendo il libro allomano, se Bactrella di Morren sia identico 

 con Metallacter, nel qual caso la demominazine proposta da Morren 

 dovrebbe essere conservata." Because first described, Bactrella undula 

 (Mtiller), Morren may be regarded as the type. 



Bactridium. A generic name proposed by Kunze (1817) for a hypho- 

 mycetous fungus. It was later used by Wallroth (1833, p. 315) for two 

 species of fungi. The genus has been commonl}^ accepted by subsequent 

 writers on mycology. As a generic name for bacteria Bactridium was 

 proposed by Fischer (1895, p. 139) to include those rod-shaped bacteria 



