Micro-organisms of Maple Sap t81 



FISSION 



The first indication of fission observed was a slight constric- 

 tion at the center of organisms which were then 3 microns in 

 length. The constrictions hecame gradually more pronounced 

 and in the course of a few minutes two daughter cells each 1.5 

 microns in length were produced. These sometimes remained 

 attached indefinitely while in other cases they separated almost 

 at once. In the specimens observed the daughter cells showed no 

 increase in length for a period varying from 20 minutes to 2 

 hours after division. There then occurred a period of rapid 

 growth followed immediately by fission. The process of elonga- 

 tion and division were observed to take place in periods of from 

 20 to 40 minutes. Fission was completed in from 5 to 8 minul 

 after the first indication of its occurrence was observed. The 

 active motility of this organism in abundant moisture made it 

 impossible to carry out these studies under conditions of optimum 

 humidity. The colonies under observation were so dry thai 

 growth continued only a few generations, and it is fair to assume 

 that the rate of growth observed is far below the maximum. 

 ( Plate YIN, figures 1 to 5). 



GROUPIXG 



The formation of chains and filaments has been noted. 

 Pseudo-zoogloea masses were observed in young cultures on 

 broth, maple sap, and other liquid media. 



MOTILITY AND IXACKU.A 



Active motility occurred in young cultures in all liquid media 

 employed. Colonies upon freshly poured plates of agar and 

 gelatin exhibited internal motility under a Zeiss A objective and 

 number 4 ocular. Motility became less marked in older culture- 

 hut was seldom entirely absent even in preparations made from 

 cultures several weeks old, whether from liquid or from solid 

 media. Flagella stains were obtained by Lowit's, Loeftler's. and 

 the Pitfield methods, in preparations made from diluted con 

 densation writer of 24-hour old agar slant culture-. These 



