PANAEOLUS CAMPANULATUS 247 



A few weeks after the culture had been started, a fruit-body of 

 Panaeolus campanulatus came up, and on March 6 it was found 

 to be shedding spores. On that day some fresh horse-dung balls 

 were placed in a crystallising dish, 1 inches in diameter and 

 2 inches high, and covered with a glass plate. They were then 

 sterilised by heating for half an hour at 100 C. in a steam 

 steriliser. As soon as the culture was sufficiently cooled, the glass 

 cover was raised, and the dung-balls were infected by rubbing 

 their surfaces with the gills of the Panaeolus. This operation was 

 performed in a few seconds with the aid of sterilised forceps. The 

 resulting culture, which was kept at room temperature, was 

 practically pure : the mycelium grew not only inside the dung- 

 balls but over their surface. The first fruit-body was observed to 

 be coming up on the thirty-first day after the culture had been 

 started, and on the thirty-fourth day it began to shed its spores. 

 A number of other fruit-bodies were subsequently produced, and 

 fresh cultures were made from them from time to time as occasion 

 required. 



The general appearance of the fruit-bodies of Panaeolus cam- 

 panulatus is shown in Fig. 83, while vertical sections are shown 

 in Figs. 84 and 87. The pileus is usually conico-campanulate 

 (Fig. 84), but under very moist conditions may become consider- 

 ably expanded although never quite flat (Fig. 87). The fruit-body 

 shown in section in Fig. 87 was grown in the laboratory under 

 very moist conditions, and exhibits the extreme amount of ex- 

 pansion which has so far been observed. A comparison of fruit- 

 bodies found in grassy fields and of fruit-bodies cultivated in the 

 laboratory has convinced me that there is usually greater expansion 

 in the latter. Probably this is due to the fact that, under the 

 artificial conditions, transpiration is hindered and the pileus-flesh 

 is thereby supplied with much more moisture than under natural 

 conditions. The pileus is rufescent under natural conditions, but 

 fruit-bodies reared in the laboratory appeared brownish or light 

 leather-colour and were certainly much less rufescent than I have 

 seen them in nature. The top of the pileus is smooth and, in 

 moist weather, somewhat viscid. The flesh is well developed, 

 especially at the disc. 



