1893.] PUBLIC DOCUMENT — Xo. 33. 217 



of a few sclerotia produced on a single young fruit (PI. I., 

 /}'.), they continued to give rise to successive new cups for 

 a period of four months. 



A comparison of the structures which have been descri])ed 

 with the recorded facts concerning the known Sderotinioi 

 shows that in the form and structure of the sclerotia, in the 

 color, form and size of the cups, and in the form and size 

 of the spores, this fungus fully agrees with the European 

 species known as Sclerotinia Ziibertiana F'k'l., and described 

 by Brefeld * and DeBary f under the name Peziza Sderotio- 

 rum. Our first cultures with this fungus were made immedi- 

 ately after obtaining the material, with the only parts of the 

 plant then available, mycelium taken from diseased cucum- 

 ber stems, and sclerotia. On prune-gelatine a small bit 

 from a mass of mycelium gave rise to abundant threads, 

 ramifying through the substratum, and producing abun- 

 dantly the "attachment organs," to be described later, but 

 giving rise neither to sclerotia nor to any spore form. Thin 

 slices from the inner tissue of sclerotia sown on the same 

 substratum gave the same result. But when similar slices 

 were sown on sterilized bread, saturated with an infusion of 

 prunes, the bread became completely enveloped in a white 

 mycelial cloud. A week after the beginning of the culture 

 the mycelium had collapsed into a thick film over the surface 

 of the bread, and a few rather small sclerotia had formed on 

 the surface. Two weeks later, no further change having 

 been observaljle and all development having evidently ceased 

 some time before, the whole was removed from the moist 

 chamber, and it was found that beneath the superficial 

 mycelial film, and occupying the space originally occupied 

 by the substance of the bread, was an almost solid mass of 

 well-matured sclerotia, varving in size from that of small 

 shot to that of a large pea. 



We may consider next the cultures with ascospores made 

 after the development of the spore cups from the sclerotia 

 afforded the means of obtaining them. When these spores 

 are sown in distilled water and protected from drying up, 

 they germinate promptly and show considerable growth by 



* Botanische Untersuchungen iiber Schimmelpilze, IV. : 1881. 

 t Botanische Zeitung, 1886, Nos. 22-27. 



