CHAPTER IX 

 CLASSIFICATION OF BACTERIA 



ROGER G. PERKINS 



Western Reserve University 



Bacteriological literature is crowded with classifications of bacteria of every sort, 

 prepared by thoughtful workers, with painstaking labor. The literature is also crowd- 

 ed with criticisms of these classifications for reasons which seem good to each author, 

 though at times he is alone in his opinion. Therefore all I dare attempt is a summary of 

 the principles under which these classifications and these honest criticisms have been 

 made, and to present them as far as possible in their relations to one another and to the 

 problem as a whole. 



Two main points of view are represented, quite distinct, although closely related. 

 The ordinary student of bacteriology is chiefly concerned with the grouping of bac- 

 terial forms to establish their general relations, involving the possibility of keys which 

 shall enable him to place any new discovery in its approximate place. The taxono- 

 mist, the specialist in bacterial classification, concerns himself further with the selection 

 of the correct names for the divisions, and the evaluation of the proper sequence of 

 order, family, genus, species, and variety, with an eye to the future. Stiles (1927), in 

 a recent address, spoke of taxonomy as the grammar of the science and emphasized 

 its essential value. He comments on the present status that "it has been the excep- 

 tion — not the rule — that pupils who study zoology have been taught the grammar of 

 the technical language they are called upon to hear, read, write and speak." This is 

 no less true in bacteriology, and the student who does more than skim the subject of 

 classification outside his own particular interests is rare. This is unfortunate, but 

 perhaps if the grammar were less chaotic it would have more students. 



Taxonomists, not only in bacteriology but in general zoology and general botany, 

 live in two camps : those who believe that for many reasons all names referring to in- 

 dividuals, varieties, species, etc., should follow the Linnaean law of priority, laid down 

 in 1 751; while the other camp holds that inasmuch as Linnaeus knew only what was 

 known in 1751, and since so much totally new information regarding classification is 

 available, we should no longer be restrained by the dead hand, but should be free to 

 express ourselves. Stiles (1927) presents sharply his idea of these alternatives. 



First let every [zoologist] adopt any technical name he wishes, or second let us all a^ree to 

 follow the Linnaean law of priority. The first alternative is subjective and leads to confusion, 

 the second is objective and makes for uniformity in all objective cases .... In general I 

 would evaluate a failure to apply the law of priority as the second most important formal 

 factor in nomcnclatoriul confusion. 



And ])crhaps llic extreme in the other camp is Enderlein, with a com]i]ete new classifi- 

 cation, and indeed a com|)lete new language. Neither side, of course, refuses lo admit 

 new titles, new definitions, and new grou[)ings, nor does it liesitate to accept the iacl 

 that our knowledge is progressive rather than fixed, l)ut the rules of the game differ. 



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