SELECTED PAPERS 



group. The objections raised by Rahn with respect to the genus Bacte- 

 roides apply also to the third family Bacteroidaceae. 



The attempt to unite in one subclass those bacteria which show a 

 tendency towards modes of reproduction other than fission is not ob- 

 jectionable in itself. However, the marked differences between the two 

 orders makes it preferable to look upon these subgroups as terminal 

 stages in the development of entirely different morphological groups 

 and therefore, in our opinion, they should be ranged separately with 

 their simpler ancestries. The advisability of the addition of several 

 Gram-negative genera to the otherwise well characterized group of 

 the Mycobacterials seems also questionable. 



The preceding remarks will suffice to make it clear that, although 

 Pribram's genera are homogeneous and much better characterized 

 than many of the genera adopted by Bergey et al., we cannot approve 

 of the way in which they are arranged in larger units. Which factors 

 can be made responsible for this difference in appreciation? There can 

 be no doubt that this is chiefly due to a different evaluation of the im- 

 portance of various characters. Although Pribram pretends to attach 

 a distinct value to the type of flagellation, yet the exceptions he allows 

 in the consistent application of this diagnostic character are so numer- 

 ous that already on this account a great deal of confusion results. 

 Pribram's neglect of the suggestion made by Orla-Jensen that one 

 should discern between 'incidental' and 'genuine' immotility - as 

 discussed earlier - is another disturbing factor. Finally it is the in- 

 sufficient appreciation of the importance of the Gram-reaction which 

 should be criticized. On the one hand Pribram fully recognizes the 

 value of this character which even accounts for the creation of several 

 new genera. On the other hand the author fails to realize the obvious 

 mutual affinities between many of the Gram-positive and many of the 

 Gram-negative genera respectively. Perhaps it is more correct to say 

 that these mutual relationships do not fully escape the attention of the 

 author, since in various places mention is made of the fact that certain 

 species may be considered as connecting links between two often 

 widely separated groups. Our principal grievance against Pribram's 

 classification is that such considerations have remained without any 

 influence on the final form of his system. 



The last contribution to bacterial classification is the important 

 paper by Prevot [1933] which has already been quoted. This study is 



302 



