Micro-organisms of Maple Sap 59. f 



.'.».. 



_, Potato. — A nanow. slimy, filiform band, becoming 

 brownish; sometimes the growth became dull and more or l< 

 rhizoid in character; the medium was more or less grayed. 



3. Agar stab. — Best growth at top, colony at first white, 

 becoming brownish; development somewhat restricted; the line 

 of puncture was at first beaded to filiform, becoming somewhat 

 villous. The medium showed a very slight fluorescence and in 

 old cultures became amber brown. 



4. Gelatin stab. — Growth best at the top; line of puncture 

 filiform to beaded; liquefaction at first crateriform, later strati- 

 form, beginning in 24 hours and proceeding rapidly at first : com- 

 plete in 62 days. 



5. Nutrient broth. — Rather slow growth ; moderate uniform 

 clouding in from 2 to ; days; transient; white membranous 

 coherent precipitate; old cultures were brownish and stringy. 



6. Milk. — Digestion apparent in about 4 days; a firm co- 

 agulum appeared in about 18 days accompanied by acid produc- 

 tion; digestion was completed in from 30 to 104 days : the medium 

 never appeared green but was more or less straw colored 

 throughout. 



7. Litmus milk. — Alkaline reaction in 4 days, succeeded by 

 slight acid production when digestion began; the litmus was com- 

 pletely reduced in 2 or 3 weeks' time. 



8. Gelatin colony. — Rapid growth : first punctiform to round 

 and entire, rapidly sinking in the saucer-like depressions of the 

 liquefying gelatin. 



9. Agar colonies. — Punctiform and round to irregular and 

 ameboid; the colonies effuse or raised and convex; the edge thin 

 entire to undulate and broken; finely to coarsely granular to 

 grttmose; commonly nucleated. Colonies dense, dark brown, 

 fringed with spiny processes occurred les> frequently. 



10. CoJin's solution. — Xo growth. 

 it. Uschinsky solution. — Xo growth. 



12. Nitrogen requirements. — Nitrogen obtained from pep- 

 tone and ammonium tartrate. 



