bib 



yneum heijermcUi Oüdemans fClastcrosporium carpophilum AderhJ.') 



Piirc cultures of Coripieum iu biii'k wounds of aluioudj peaclial- 

 uioiid, peac'li, chcn-v, plum, bird's cherry, sloe, virginiau jiluni, develop 

 with remarkable quickness and soon make the bark die off, evidently 

 in consequence of the secretion of a poison. Ai-ound the dead cells 

 the necrobiotic are found from which the stimulus issues, which, 

 penetrating into the cambium in the usual way, forms gum 

 canals in the yoiuig wood. Many mycelial threads of the parasite 

 itself are then cytolised and converted into gum. I thiidv this fact 

 remarkable and a strong argument for the material nature of the 

 stimulus. 



Undamaged branches are with dilïiculty infected by the parasite, but 

 it is easy, even by very slight ;W0unds and artificial infection, if 

 only the wounds be numerous, to obtain great ((nantities of guni. 

 This circumstance explains why nui'sery men dread wounds in the 

 trunks and branches of stone-fruit trees. 



In the green shoots, especially of the peach, the formation of 

 anthocvan is observed in the enfeebled tissue around the wounds 

 infected with Cori/neinn when exposed to sunlight. -J 



The supposition that secretion products of the parasitic catei'pillar 

 or the Fungus could be the direct cause of the stimulus, is contrary 

 to the j)Ositively existing relation between mechanical wounding and 

 gum'mosis. 



Gum canals in the fruitjiesh of almond and peac/ialmond. 



To the preceding facts, long since stated, I wish to add the following. 

 Already in my tii'st paper of 1883 I called attention to the circum- 



1) Betjerinck, Onderzoekingen over de besmettelijkheid der gomziekte bij planten. 

 Versl. d. Akad. v. Wetenscli. Amsterdam, 1888, — Contagiosité de la maladie de 

 gomme chez. les plantes. Archives Néerlandaises, lé Sér., T. 19, Pag. 1, 1886. . — 

 G. A. J. A. OuDEMANS, Hedwigia, 1883, N". 8. — Saccardo, Sylloge Fungorum, 

 Vol. 3, Pag. 774, 1884. — Aderhold, IJeher Clastero82)orium ca rpophihmi (LÉv.) 

 Aderh. nnd dessen Beziehung zum Gummifluss des Steinobstes. Arbeiten der 

 Biolog. Abt. am Gesundheitsamte zu Berlin. Bd. 2, Pag. 515, 1902. Aderhold 

 has experimented with pure cultures of Goryneum, which I had made and sent 

 him. He himself has not executed any isolations of gum parasites. His determination 

 as Cluster osporium amygdalearuni (Lev.) is thus founded on the imperfect de- 

 scriptions from the older mycological literature, in which Oüdemans was no doubt 

 better at home than he. Like Lindau I reckon Cluster osporium to another family 

 than Goryneum. 



~) The apperance of anlhocyan in the light is commonly a token of diminished 

 vitality and often a consequence of necrobiose in the adjoining cells. Hence, wounds, 

 poisons and parasitism cause anthocyan production in the most different plants. 



