855 



If the analyses of the sap from bleeding grapevines are studied closely^, 

 it is found that besides small quantities of organic substances, nitrogen, 

 phosphoric acid and calcium are also present, i. e. it may be considered as a 

 nutrient solution very well suited for infection by micro-organisms and for 

 their increase. Ludwig has studied this thoroughly". In a number of pub- 

 lications he describes a white slimy exudation in the oak, birch, Saliceae, etc., 

 due to Leuconostoc Lagerheimii Ludw. with which are associated various 

 fermenting fungi {Saccharomyces Ludwigii Hans, etc.). A "hrotvn slimy 

 exudation," found in apples, birches, poplars, horsechestnuts and other fruit 

 and street trees, showed Micro-coccus dendroporthos Ludw., with which is 

 associated Trula monilioides Cord. Ludwig found a "red slime" in the late 

 summer on the stumps of old, healthy beeches and observed in it a filament 

 bacterium (Leptothrix?) and Fusarium moschatum. He met with the same 

 bacterium in a yellowish white bleeding sap with a gelatinous, granular con- 

 sistency in lindens and sometimes in birches. He also found toward the 

 middle of April on fresh branch wounds of a hornbeam a milky looking slime 

 which contained Endomyces vernatis Ludw. together with alcohol producing 

 yeast. In one of his later works^ we find mention of mites (Hericia) and 

 eelworms (Rhabditis) as animal companions of such bacteria and fungi. In 

 the Zeitschrift fiir Pflanzenkrankheiten 1899, p. 13, we find a Hst of all the 

 infesters of slimy exudations which have been confirmed not only for 

 Germany but also for the tropics. Of course this list will be constantly 

 increased according to whether the micro-organisms, belonging to specific 

 localities, have had opportunity to infect the bleeding wounds of trees. 



The organisms here named may be considered to be injurious to trees 

 only in so far as their infection delays or prevents the closing of the wound. 

 Wounds which have been made by frost, lightning, animals, etc., and intro- 

 duce periodic bleeding, form the primary cause of the slimy exudations. If 

 it is found necessary agriculturally to remove such weakening causes, the 

 only method possible would be to cut out carefully the diseased places and 

 paint the fresh edges of the wound with coal tar. 



1 Ravizza, F., tJber das Thranen der Weinrebe usw. Staz. sperimentali 1888; 

 cit. Biedemiann's Centralbl. f. Agrik. 18S8, p. 541. According- to investigations by 

 Neubauer and v. Canstein (Annalen der Oenologie, Vol. IV, 1874, Part 4, p. 499) the 

 sap of the grapevine (gathered in the dry year 1874) which, in its fresh condition, 

 is as clear as water, and neutral, but easily becomes clouded by bacterial growth and 

 then reacts as an alkali, contained at the time of experiment 2.1204 g. of solid matter 

 per liter, of which 0.7408 g. were mineral elements and 1.3796 g. organic substance. 

 An analysis of the ash gave 10.494 percent, potassium; 1.437 percent, sulfuric acid; 

 0.188 percent, ferric oxid; 2.822 percent, phosphoric acid; 41.293 percent, calcium; 

 5.534 percent, magnesia; 34.791 percent, carbon dioxid; 2.857 percent, chlorid; 0.810 

 percent, silicic acid in the raw ash. Besides these acids, an organic magnesia salt, 

 gum, sugar, and calcium tartarate, inosit, succinic acid, oxalic acid and unknown 

 extractive substances, were found. Rotondi and Ghizzoni (Biedermann's Centralbl. 

 1879, p. 527) also mention besides starch, sugar which the Neubauer investigations 

 had not found in the fresh sap. Only the volatilized sap which, with the giving off 

 of carbon dioxid and the elimination of calcium phosphate, together with a yellow 

 coloration, had a weakly acid reaction, showed all the sugar reactions. 



2 Ludwig, F., Der Milch- und Rotfluss der Baume und ihrer Urheber. — ^tJber das 

 Vorkommen des Moschuspilzes im Saftfluss der Baume; cit. Zeitschr. f. Pflanzen- 

 krankheiten 1892, p. 159, 160. 



3 Ludwig, P., tJber die Milben der Baumfliisse und das Vorkommen des Hericia 

 Robin! Canestrini in Deutschland. Zeitsch. f. Pflanzenkrankh. 1906, p. 137. 



