Micro-organisms oi? Maple Sap l s; i 



upon the material even when used with heat for 20 I" 30 minuti 

 while the blue counter stain acted upon the organisms faintly. 

 Part of the bacilli <»n the films thus treated showed an unstained 

 envelope lighter than cither the body of the organism or the field 



and from .5 to .75 micron in diameter. When Welch's capsule 

 stain was employed the organisms from sap cultures appeared 

 distinctly stained, surrounded by a transparent envelope .75 to 1 

 micron in thickness. Films from carbohydrate agar prepared by 

 Welch's method showed a colorless envelope upon practically 

 all organisms. Flagella preparations from 24 hour agar slants 

 stained by Loeffler's method with anilin gentian violet often ex- 

 hibited the capsule clearly stained. (Plate X. figure 1 ). 



INVOLUTION FORMS 



In a few cases oval refractive bodies suggestive of spores 

 were seen in preparations from cooked potato cultures several 

 weeks old. Transfers taken from such cultures were invariably 

 killed by heating for 10 minutes at 55° C. and attempts to stain 

 the bodies by the usual methods for spores gave negative results. 

 These bodies were deemed to be vacuoles. 



STAINING REACTIONS 



Preparations made from 24 hour old cultures upon nutrient 

 broth and nutrient agar were readily and deeply stained by cold 

 watery solutions of the anilin dyes, by Ehrlich's anilin water 

 gentian violet and by carbol fuchsin. Many of the rods stained 

 by carbol fuchsin exhibited plasmolysis. It is an interesting fact 

 that organisms from broth and agar cultures were deeply stained 

 by exposure for 10 seconds to cold carbol fuchsin. while this 

 stain used either cold or hot was totally ineffective with Richard 

 Muir's method of capsule staining applied to organisms from sap 

 cultures, as reported under the head "capsule." The organism 

 was decolorized by the method of Gram. 



