CLASSIFICATION OF WATER BACTERIA 287 
In order to make some definite bases for describing ‘cultures the 
committee of the American Public Health Association suggested the 
following scheme which has been outlined by Savage (1906) as follows: 
I. Source and habitat. 
II. Morphological characters. 
Form. Manner of grouping, dimensions, staining reactions 
motility, spores, capsules, involution forms. 
ITI. Cultural characteristics. 
Mode of growth in and upon nutrient broth, gelatin rlates, 
gelatin tubes, agar plates, agar tubes. 
IV. .Biochemical reactions. 
Action upon milk, carbohydrates, nitrates; production of indol; 
relation to free oxygen; temperature relations; pigment 
formation; liquefaction of gelatin. 
Such a scheme as outlined above tends toward greater uniformity in 
the examination of bacteria in water. It seems to be the general ten- 
dency at the present time to arrange bacteria into groups and this is the 
best method for handling the flora of a substance like water. Tanner 
(1918) has shown that the fluorescent bacteria in water compose a closely 
related group. Wyatt Johnston (1894) early called attention to the 
grouping of water bacteria. In his paper, he discussed the tests which 
should be applied to separate bacteria into these groups. He analyzed 
235 described organisms and reached the following conclusions: That 
points of difference are given more attention than resemblances. In 
the grouping of bacteria a single strongly marked characteristic peculiar 
to a few species is of more value than a number of minor details but the 
members of any group should not differ unduly in regard to minor 
points. About this time the American Public Health Association real- 
ized the necessity of uniform procedures for the study of bacteria and 
appointed a committee to study methods for that purpose. This com- 
mittee reported in 1897 and recommended the following procedures: 
Necessary Information: 
I. Source and habitat. 
Il. Morphological characters. 
Form, dimensions, grouping, staining, capsule, flagella spores, 
pleomorphism, involution forms. 
