84 RESEARCHES ON FUNGI 



C. cordisporus. 1 Later on, if the. dung is kept moist, certain other 

 Coprini may spring up, among which may here be mentioned : C. 

 stercorarius, C. narcoticus, and C. sterquilinus. The pilei of Coprinus 

 lagopus are at first white and covered with a hairy veil (cf. the young 

 fruit-bodies on the dung-ball in Fig. 21, p. 72) and subsequently, 

 after expansion, cinereous grey and bearing thin, easily-rubbed-off, 

 fibrillose scales (Figs. 20 and 21). The presence of these fibrillose 

 scales at once distinguishes the fruit-bodies of C. lagopus from 

 those of all the other species in the culture except those of the 

 relatively gigantic C. sterquilinus with which we shall become 

 acquainted in Volume III. The size of these spontaneously 

 developing fruit-bodies is very variable indeed, the largest being 

 about the size of those shown in Fig. 20 and the smallest less 

 than a quarter as large ; but all of them, from the largest to the 

 very smallest, exhibit upon their pilei the characteristic, easily 

 detachable, hairy scales. To prepare the medium for a pure 

 culture, all that one needs to do is to take some fresh horse-dung 

 balls, put them in a large crystallising dish, cover the dish with a 

 glass plate, and sterilise the whole at 100 C. for one hour in a steam 

 steriliser. This ensures the killing of all the fungus spores in the 

 medium and most of the bacteria. To infect the medium, one 

 takes an expanded pileus of Coprinus lagopus with a pair of sterilised 

 forceps, lifts the covering plate of the dish, and holds the pileus 

 for about half a minute over the dung-balls in succession. During 

 this operation many spores are discharged from the gills and fall 

 on 'to the dung. The plate is then replaced on the top of the dish 

 and the culture set on a table in the laboratory. The spores 

 germinate, the germ-tubes rapidly develop into mycelia, the 

 mycelia soon anastomose with one another, and fruit-bodies come 

 up on the dung-balls at the end of about three weeks. I have 

 seen the life-cycle from spore to spore accomplished in exactly 

 21 days. The fruit-bodies which come up in pure cultures of the 

 kind just described are usually much larger than those which come 

 up spontaneously on horse dung in competition with other species. 



1 For nomenclature vide Jakob E. Lange's useful revision of the genus Coprinus 

 in his " Studies in the Agarics of Denmark," Dansk Botanisk Arkiv udgivet of Dansk 

 Rotanisk Forenig, Part IT. No. 3, 1915. 



