HOTSOX. CULTURE STUDIES OF FUNGI. L'lio 



cillium agaricinum Link, var. clavisedum (Mich. II, p. 577) is asso- 

 ciated with it. 



A large number of specimens of Geoglossum, with plenty of Sphag- 

 num and leaf mould about each, were collected — some infected, 

 others not — and were grown under bell jars or in a large germinating 

 vessel with a glass top. It was thus kept growing for nearly two 

 months, until it could be determined whether the Papulospora would 

 grow as a saprophyte on artificial media. A number of tube cultures 

 were made of the bulbils on various kinds of media, the most success- 

 ful of which were the ascoma of Geoglossum itself. About a dozen 

 large specimens of these with long stalks were selected and each put 

 in a test-tube which had previously been supplied with about half 

 an inch agar. These were then sterilized in an autoclave, the object 

 of the agar being simply to hold the specimen in place and thus lessen 

 tin' chances of contamination in making the transfers, etc. On this 

 medium a pure culture was eventually obtained, which was then 

 transferred to other media such as potato, corn meal, chestnut, 

 horse dung, etc., hardened with agar. This fungus grows fairly well 

 as a saprophyte, better on hard than on soft media such as potato 

 and bran, but very slowly on horse dung, on which, after a month, 

 it had not grown much more than an inch from the point of inocula- 

 tion. Associated with the Papulospora on the ascoma were found, 

 among other fungi, specimens of Pleurage anserina (Rabh) Kuntze 

 and Verticillium agaricinum Link, the latter producing in pure cul- 

 tures - ( r. large and conspicuous, brownish sclerotia. 



On its natural host Papulospora Candida forms conspicuous white 

 blotches spreading over the upper portion of the ascoma (Figure 47, 

 Plate 4'. and if not too wet, extending down the stem. Although the 

 ho t is usually found in damp sphagnum swamps, the parasite is 

 largely confined to those specimens that grow tall, so that their tops 

 are comparatively dry. The mycelium is white, procumbent, branch- 

 ing copiously, but soon becoming indistinguishable as such, even with 

 ;i nod hand lens, mainly on account of the large number of bulbils 

 that are formed which give the whole fungus a powdery appearance. 

 When examined under a microscope the mycelium is opalescent, 

 owing to the presence of numerous oil globules (Figures 42, 44, Plate 4) 

 and other colorless material in the cells. The cultures become com- 

 pletely covered with the white powdery bulbils which a little later 

 assume a characteristic cream color. 



The bulbils. — During the process of development of the bulbil a 

 short lateral branch divides up into a number of cells and the end 



