M [CRO ORGAN tSMS 01? M Al'l.K SAP 



and from it, as a parent stuck, a sub stock was maintained. From 

 the sub-stock an inoculation stock was rejuvenated occasionally 

 and subjected to retransfer every 24 to 48 hours. Frequent 

 replating assured the purity of the strains. Unless otherwise 



stated inoculations were made from 24 to 48 hour broth cultui 

 and incubation was at 25 ° C. Gelatin media were incubated at 

 20 C. 



DETAILED FEATURES oi' Till'. FORTY-TWO STRAINS 



The immediate object of the preliminary studies was to 

 separate the forty-two strains of fluorescent bacteria into groups, 

 in order that type organisms might be selected for a more ex- 

 haustive study. To this end attention was directed primarily 

 toward the characteristics which are expressed by the group 

 number, (Descriptive Card, Society of American Bacteriol- 

 ogists) ; but considerable additional data was secured on the 

 morphological, cultural, physical and biochemical characters of 

 the organisms. Therefore the discussion of the preliminary work 

 follows in a general way the detailed features as outlined in the 

 Society Card. For the group numbers of the strains and the 

 method of separating the series into groups, see pages 550-551. 



I. Morphology 



1. Form. — The organisms are all motile rods. I 'reparations 

 from 24 hour agar slant cultures of all -trains stained by Lowit's 

 method for flagella showed that some strains typically have one. 

 and others three or six, polar llagella, chains frequently exhibiting 

 numerous long flagella in a polar tuft. Strain CXV also has 

 lateral flagella (c. f., pp. 546, 555). 



2. Grouping. — Short chains of two cells were typical but 

 longer chains were not uncommon. A surface scum or pellicle 

 was usually present on liquid media. 



3. Motility. — Rapidly and quite persistently motile. 



4. Bndospores. — None were demonstrated with stains or 

 by thermal death point determinations. Several common spore 



