Ohservations on the "Slime-fluxes" of trees, 177 



of hornets, stag beetles, wasps, bees and flies which fed ravenously 

 on the frothy exudations and e\*idently suffered somewhat from 

 intoxication in consequence. Ludwig attributed to them the 

 dispersal of the flux. 



The initial fermentation is brought about, in Ludwig's 

 opinion, by a fungus which he named Endomyces Magnusii, and 

 which forms asci resembhng those of yeasts. In its mycehal 

 form it resembles a large Oospora [Oidiiun) \\ith preponderating 

 unilateral branching. This is accompanied by SaccJuiromyces 

 Liidungii Hansen, a yeast regarded at first by Ludwig as a 

 stage of the Endomyces, and, according to Ludwig by Leuconostoc 

 Lagerhcitnii Ludw., a bacterial form, somewhat resembling 

 L. mesetiteroides Cienkowski, the ' ' frog-spawn '" of sugar factories. 



Hansen (4\. in Denmark, was luiable to find these three 

 organisms except in one case out of seventeen. Holtz(9), near 

 Karlsruhe, found the oak fluxes only on the main trunk and 

 usually somewhat low down. They started to flow in May and 

 June and had all stopped by the first half of August. He found 

 that an Oidium, resembling the Oidium stage of Ludwig's 

 Endomyces was occasionally, though not constantly, present 

 He could not identify Leuconostoc Lagerhcimii . 



2. White Flux of Willows. 

 (a) General. 



At the end of May, 1922, and again in 1923, curious exuda- 

 tions were noticed on the trunks of pollard willows on the banks 

 of the Cam near Cambridge. They flowed in every case from 

 cracks and small holes on the main trunk, often near the ground, 

 were verv frothv, pure white in colour, and had a strong smell 

 of beer. Numerous ants and small flies had e\-idently been 

 attracted by the smell and were crawling over and feeding on 

 the fluxes. 



These exudations remained active till about the middle of 

 Julv. when they became more shmy and finally dried up, lea\ing 

 rusty brown marks. In the later stages they were much \'isited 

 by wasps and hornets, and contained insect lar\'ae. In com- 

 parison N%-ith the broN^Ti fluxes their volume was ver^' smaU, and 

 no damage was done beyond a shght disintegration of the bark, 

 to which they were apparently totally confined. 



(b) Organisms present. 



A. Oospora {Oidium) sp. (probablv = Oospora Ludwigii (Hans. 



Sacc. et D. Sacc). 



The oidia and hyphae of this fungus were found in most of 



the specimens of white flux of ^^■illows which the writer examined, 



but it was not universally present, and the greater part of the 



