CLASSIFICATION OF WATER BACTERIA 289 
X. Yellow non-liquefying forms. Probably related to IX. 
XI. Colorless capsulated forms. 
XII. Yellow capsulated forms. 
XIII. B. prodigiosus types. 
XIV. Rapid liquefiers, colorless, pronounced putrefactive tendencies. 
XV. B. subtelzs like group. 
XVI. Yellow sarcina-like bacteria. 
XVII. Rose-colored micrococci. 
XVIII. Fungus forms. 
XIX. White micrococci (VM. candicans). 
XX. Lemon yellow gelatin liquefiers. 
XXI. Short oval cocci forming a red pigment. 
That this classification of water bacteria is artificial was realized by 
Ward for he made the following statement: ‘‘ My work goes to show that 
species cannot be made out but that the limits of the species are, in most 
cases, far wider than is assumed in descriptions—in other words that 
many so-called species in books are merely variated forms, whose char- 
acters, as given, are not constant but depend on treatment. How far 
this is true for any given case will have to be tested on the particular 
form in question.” 
Fuller and Johnson (1899) studied water bacteria from a river in 
America and arranged their strams into thirteen groups. They realized 
weaknesses in their system and state that too much importance was 
given to morphological data and too little to cultural studies. Dif- 
ficulty was also experienced in separating short rods from cocci. This 
classification has formed the basis for much systematic work in bac- 
teriology. Their groups are given below: 
I. Fluorescent forms. 
IJ. All red chromogenic forms. 
TII. All orange chromogenic forms. 
TV. All yellow chromogenic forms. 
V. All violet chromogenic forms. 
VI. All non-fluorescent, non-chromogenic, gelatin liquefying bacteria, 
forming proteus-like colonies on gelatin. 
VII. All non-fluorescent, non-chromogenic, gelatin liquefying bacteria, 
forming subtilis-like colonies on gelatin. 
VIII. All non-fluorescent, non-chromogenic, non-proteus like non- 
subtilis-like bacteria which liquefy gelatin and ferment car- 
bohydrates with production of gas. 
