Studies of Bacillus Radicicola of Canada Field Pea 17 



is detected. Motility seems to be influenced by environmental conditions. 

 This point has not been studied extensively, beyond the observation that on 

 nitrogenous media the motility is lost sooner than on nitrogen-free media. 



Since the generic name ot the organism depends on the presence and the 

 place of attachment of flagella, and smce there has been so much un- 

 certainty on this point, an effort was made to demonstrate the number 

 and the arrangement of the flagella. Beyerinck (1890) was the first who 

 claimed to have isolated the organism in a pure culture. He described 

 it as having one polar flagellum, and named it Bacillus radicicola. In 

 1905, Moore, agreeing with Beyerinck as to the number of flagella and 

 wishing to conform to Migula's classification, changed the generic name 

 from Bacillus to Pseudomonas. Edwards and Barlow (1909) found only 

 one long, whiplike flagellum, thus agreeing with Beyerinck and Moore. 

 De' Rossi (1907) was the first investigator who found the organism of 

 Vicia faba to have about eight flagella with a peritrichic arrangement. 

 Zipfel (1912) agreed with de' Rossi, stating that the organism has numerous 

 flagella. In 1912 Kellerman, using a special method, also succeeded in 

 staming the organism of several leguminous plants. He likewise found 

 the organism to have several flagella peritrichically arranged. 



In this mvestigation the following method was used for staining the 

 organism of Canada field pea for flagella: 



An agar slope culture twenty hours old, on medium 335 at 24° C, was 

 very carefully transferred into 3 cubic centimeters of sterile distilled water 

 in a test tube. This was allowed to stand for about four hours at a con- 

 stant temperature, without being shaken or disturbed in any way. A 

 drop of this infusion was placed on a cover glass and allowed to dry at 

 room temperature, and when dry it was stained. 



It was essential that the cover glasses should be clean. To this end 

 they were treated with a cleaning solution of potassium bichromate and 

 sulfuric acid, washed in water, placed in alcohol, and finally dried with 

 a piece of cheesecloth which had been treated with ether in order to get 

 rid of any fats. The cover glasses were then placed in a petri dish and 

 baked in the oven for three hours at 200° C. If cover glasses are treated 

 in this way a large amount of difficulty in the staining of flagella is 

 avoided. 



Pitfield's mordant as modified bj^ Muir, and carbol fuchsin, were used 

 for staining. The mordant has the following composition: 



