556 Bulletin 167 



quently 2 and sometimes as many as 5 cells occurred side by 

 side in the same capsule, with flagella arising about the periph- 

 ery of the envelope (c. f. Plate X, figure 3). 



Measurements obtained on the capsule preparations follow : 



Strain CXLV. — Material from 10 day broth cultures was 

 stained by Richard Muir's method and capsulation demon- 

 strated. Parallelism of cells within the capsules was absent 

 with this strain. 



5. Zoogloca. — Not observed. 



6. Involution forms. — Unusually long cells were common 

 in old cultures. 



7. Staining reactions. 



Gram's stain. — Films from 4 day agar colonies of the 13 

 strains were stained as follows: (22:103). 



Treated with anilin gentian violet (22:101) i 1 /* minutes, 

 washed in water; treated with Gram's solution i J / 2 minutes, 

 and immersed in absolute alcohol 4 minutes. All of the fluores 

 cent organisms were Gram negative (21 :888). All strains 

 except Ps. alba showed some granular spots which failed to 

 decolorize in 4 minutes. Strain CXV remained deeply stained 

 even after 15 minutes in absolute alcohol. 



Gram's stain with amyl alcohol (29:108). — Films of strains 

 CXII, CXV, and CXL were stained as above, but amyl alcohol 

 was used 5 minutes for decolorizing. Strain CXII retained 

 the stain faintly, some cells more than others, and a bi-polar 

 effect was noticeable. With CXV the stain was irregularly 

 retained, the cells having a granular appearance. Cells of 

 strain CXL were only partially decolorized even after 15 

 minutes exposure to amyl alcohol. 



