S. G. Paink 211 



agar, the sixth transfer from the original, incubated at 22° C. The 

 colony had attained a diameter of 4 mm. The fihn was fixed by ten 

 minutes' immersion in 4 per cent, formah'n, stained for ten minutes in 

 aqueous methyl violet, and examined in oil. The length of the organism 

 varied from 0-9/x to 1-7/i and the breadth from 0-4/x to 0-5/x. The growth 

 was very viscous and suggested the presence of a capsule; when a 

 suspension of the organism in normal saline was examined by dark- 

 ground illumination, however, no sign of a capsule was discovered. 



Motility and Flagella. The organism is actively motile in young 

 cultures in broth and upon agar, but it comes to rest early, frequently 

 after 24 hours at air temperature on solid media. The movement is of 

 a free swimming type without other specific characteristic. The flagella 

 have been stained by Stevens' modification of Van Ermengen's stain 

 and by a new method devised by the late Professor H. G. Plimmer^. 

 The flagella are two to four times the length of the organism, one or 

 two in number, occasionally three and more rarely four or five, arranged 

 at one pole. (See Fig. 5.) The organism is therefore a Pseudomonas. 



^ I \ 



Fig. 5. Camera drawing from a preparation stained by the method of Plimmer. 



Staining. The organism stains well with carbol fuchsin, gentian 

 violet and methyl violet, does not stain by Gram's method, is not acid 

 fast, and gives negative results with the usual capsule stains. 



^ I hope with Dr R. H. A. PHmmer's permission to publish a description of this staining 

 method if the details can be worked out from the data left by Professor Plimmer. 



