482 Bulletin 167 



showed each rod to have from 2 to 7 peritrichiate flagella fre- 

 quently developing a length of 15 microns. (Plate VIII, fig- 

 ure 6). 



SPORES 



No indications of spores were observed although search was 

 made both by microscopic methods and by means of thermal 

 death point determinations in old cultures upon agar and upon 

 cooked potato. 



CAPSULE 



Microscopic examination of the mucilaginous deposit found 

 in cultures upon maple sap as described under "Cultural Char- 

 acters" revealed an envelope of almost transparent material and 

 about 1 micron in thickness covering the organism. In unstained 

 preparations, it was most readily observed by first placing the 

 organisms in perfect focus with the diaphragm slightly open, and 

 then reducing the light, when the colorless envelope became faintly 

 though distinctly visible, presenting a well defined periphery. 

 Organisms from the surface growth of carbohydrate agars showed 

 a similar capsulation when mounted without the use of water. 

 Organisms from carbohydrate agar condensation water or from 

 milk showed a similar phenomenon, but the envelope was less 

 clearly defined and scarcely more than .5 micron in thickness. 

 Stained preparations from maple sap and milk cultures were dis- 

 appointing. Sap preparations left to dry in the air formed a gela- 

 tinous mass about one-half the size of the original drop of 

 culture placed on the cover slip, and the volume of this material 

 could not be further reduced in drying with heat without charring 

 the preparation. Richard Muir's capsule stain was tried repeat- 

 edly upon these preparations, but washing in water after the 

 first mordant almost instantly dissolved the gelatinous mass and 

 left the cover slips without a film of organisms. This difficulty 

 was partially obviated by fixing in glacial acetic acid before the 

 mordant and substituting a 2'/< salt solution for water in the 

 subsequent washing. The stain, carbol fuchsin, was inactive 



