Micro-organisms of Maple Sap 529 



tested out at 20 C. with similar results. The growth was best a< 

 the top with the puncture beaded to filiform. Restricted develop- 

 ment occurred along the puncture below the liquid gelatin. 

 Crateriform liquefaction becoming stratiform was typical of the 

 group. The reaction began in from i(> hours to 3 to 5 months. 

 Several weeks or longer was required to complete the liquefaction 

 of 7 cc. of the medium. Fluorescence was not marked, old cul- 

 tures showing it only faintly. 



One set of cultures in duplicate held under observation over 

 eight months yielded noteworthy results. Seven strains began a 

 typical liquefaction after from three to five months, but the time 

 required for complete liquefaction of 7 cc. was not determined. 

 At the end of S>y 2 months control plates were poured and the 

 organisms found to be present in pure culture. The organisms 

 recovered were fluorescent and capable of producing hydrogen 

 sulphid, the latter property being- peculiar to these seven strains 



5. Nutrient broth. — A surface scum or a thin membranous 

 pellicle, often wrinkled, was usually present. Clouding was strong 

 at first, the medium becoming yellow-green fluorescent and clear- 

 ing with a deposition of a more or less coherent sediment. 



6. Milk. — Fresh centrifuged milk reacting +12 to -+14 

 Fuller's scale, and sterilized by the fractional method, was used. 

 In from one to ten days a watery layer appeared at the surface 

 with a jelly-like thickening and greenish discoloration of the 

 substratum in all cultures except those of the following strains : 

 CXL, CXLL CXLII, CX1J11. CXLVI, CXLYII. XVI, 

 XXXYI, L, LI, and LIV. After 35 days - incubation, CXLVII, 

 XVI, XXXYI. XXXVIII, LI, and LIV showed doubtful clear- 

 ing. Strains CXL, CXLI, CXLII. CXI J II. CXLVI, and L in 

 all trials remained unchanged for about 3 months, when a very 

 slow digestion appeared. 



7. Litmus milk. — Litmus milk was prepared by the addi- 

 tion of 2 c /r of a saturated solution of chemically pure litmus to 

 fresh centrifuged milk and which was then sterilized by the inter- 

 mittent method. 



