NOMENCLATURE 



699 



still, in our opinion, good reason for continuing this mode of classification, but 

 there is now perhaps reason for proceeding still further in the taxonomic differentia- 

 tion of these organisms. As we have already explained in the previous chapter, 

 the term Salmonella has got for practical purposes to be accepted generically, 

 in spite of the logical inconsistencies which its adoption leads to. If we accept 

 this, then we are forced to separate off the dysentery bacilli from the Bacterium 

 genus, and classify them under a separate generic name, such as Shigella. The 

 specific names can then follow easily. American workers have adopted the sj^ecific 

 name amhigua in place of schmitzi, and of far ady sentence in place oi flexneri. 



Both Schmitz's and Flexner's bacillus are so well known by the names of their 

 discoverers that it is a pity not to perpetuate this association in the nomenclature 

 of the dysentery group. The strict systematist may object that the terms amhigua 

 and jparadysentericB have priority, but this argument has little power to move us. 

 The primary purpose of nomenclature is utility, and to insist on an inapt and 

 uninformative specific name merely on grounds of botanical convention is to forget 

 that the Sabbath was made for man and not man for the Sabbath. The classifi- 

 cation and nomenclature that we would suggest as being the most valuable for 

 teaching purposes is given diagrammatically in Fig. 146. 



Mannitol 



Sh. shigcB 



Some 



para-Shiga 



bacilli 



Indole 

 Rhamnose 



\ + 



Sh, schmitzi 



Some 



para-Shiga 



bacilli 



Dulcitol 



Sh. jlexneri 



+ 



Lactose 



Indole 

 Sorbitol 



4- 



Sh. alkalescens 



Sh. sonnei Sh. dispar 



i = V 



ii = W 

 iii = X 

 iv = Z 



V = 103 

 vi= P119 

 ' Sh. boyd 



i= 170 

 iv = 274 



? Sh. boyd 

 ii = P2881 late 

 iii = Dl I fermenters 



Fig. 146. — -Tentative Classification of the Dysentery Bacilli. 



Note. — Shigella newcastte may or may not ferment mannitol, and has 



been omitted from the figure. 



For two recent reviews of the dysentery bacilli reference may be made to 

 Neter (1942) and Weil (1943). 



REFERENCES 



Alt, M. (1938) J. Egypt, med. Ass., 21, 650. 



Amako, T. (1908) Z. Hyg. InfektKr., 60, 93. 



Andrewes, F. W. (1918) Lancet, i. 560. 



Andrewes, F. W. and Inman, A. C. (1919) Spec. Rep. Ser. med. Res. Coun., Lond., No. 42. 



AoKi, K. (1921) Tokohu J. exp. Med., 2, 142; (1923) Ibid., 4, 12. 



