Observations on the "Slime-fluxes" of trees. 175 



apples than on others; thus "Lord Grosvenor" appears to be 

 somewhat susceptible, although similar fluxes have been found on 

 trees of "Newton Wonder," ""Chivers" Seedling' and "Duchess 

 of Oldenburg." 



The fluxes are white, pale pink, or black in colour, of a watery 

 or slimy consistency, and proceed entirely from the centre of 

 the wood of the cut branch. They are prevalent all through the 

 year, but tend to dry up during the summer. They apparently 

 do httle damage to the trees except after a prolonged period, 

 when rotting of the wood and bark takes place slowly. 



According to Ludwigdr), the fluxes of apple-trees are prac- 

 tically the same as those found on elms and horse-chestnuts. 

 The writer has found, however, that, around Cambridge at least, 

 they have a pecuhar and interesting flora of their own, composed 

 of three kinds of yeasts. Fluxes have never been seen on plum- 

 trees, as described by Massee(8). 



The apple fluxes appear to originate as a physiological exuda- 

 tion similar to that described in the brown fluxes of elms. 



(b) Organisms present. 



A. Yeast I. 



Cultural characters. On beer-wort gelatine after 14 da\-5 a 

 flat white growth with a wa\y edge, central raised portion, and 

 radial lines. No hquef action. Growth on agar ver\- similar. 

 On beer- wort a film is formed after 24 hours at 26" C. Xo 

 fermentation. Acid from glucose (14 days). Xo spore formation. 

 Marked growth at i' C. 



Morphological characters. On soUd media and beer-wort, fihn 

 h\"phae are formed. Cells 10 x i-Sfi, branching irregularly by 

 budding. Separate cells from a three days' culture on beer- 

 wort gelatine average 9 \ 4 /x and are vacuolate. 



B. Yeast II. 



Resembles Yeast I in appearance. 



Cultural characters. On beer-wort gelatine forms small round 

 grev colonies with shghtiy raised white centre with crater-like 

 markings, deep radial furrows and indented edge. The young 

 colonies have beautifully branched h^phae at the edge. Does not 

 hquef\' gelatine. On beer- wort after 24 hours at 26^ C. a thick 

 grev surface film is formed. X'o alcoholic fermentation or spore 

 formation. Acid produced from glucose and lae\-ulose after 

 14 days. 



Morphological characters. Resembles Yeast I, but cells 

 average 3-5 fi in diameter. From a five da^'s' beer-wort film the 

 cells measured 9 x 3-6^. 



