3o8 



RESEARCHES ON FUNGI 



immediately thereafter it puffed vigorously and, in so doing, gave out 

 an audible sound. Had the fruit-body been left undisturbed where 

 it had developed, probably it would have puffed sooner or later owing 

 to its being touched by a passing animal, blown upon by rising wind, 

 or partially dried by the loss of water vapour to the surrounding 

 atmosphere as this became less humid. 



Urnula Craterium. — Urnula Craterium, the Burnt-out Crater 

 Fungus, is somewhat rare in Europe but is common in North 



America, and I have met 

 with it several times in 

 Canada on the shores of 

 the Lake of the Woods and 

 of Lake Winnipeg. It 

 grows on the ground in 

 woods and is attached to 

 buried or partly buried 

 sticks (Fig. 150) or to saw- 

 dust, etc. (Figs. 169 and 

 170, pp. 335 and 336). 

 The fruit-body is stipitate 

 and the stipe is continued 

 upwards into a deep black 

 cup. A mature fruit-body 

 in the open, when touched, 

 puffs vigorously, and the 

 spore-smoke is shot out of 

 the mouth of the cup. 

 Here, as in Aleuria vesi- 

 culosa and Galactinia badia, the safe exit of the spores from the 

 cup is due to the ends of the asci being heliotropically turned to 

 the source of brightest light and therefore to the opening in the 

 top of the fruit-body. 



The paraphyses of Urnula Craterium are thin, septate, much 

 branched and brown above. Their end-branches are straight and 

 show no signs of heliotropic curvature, thus contrasting with the 

 asci. In U. Craterium, therefore, while the asci are heliotropic, the 

 paraphyses are anheliotropic. 



Fig. 149. — Galactinia badia. Diagram to illus- 

 trate an experiment on the direction of 

 discharge of the asci. A fruit-body matured 

 its spores in a damp-chamber. A piece of 

 its side was then very quickly cut away, 

 removed from the damp-chamber and, with 

 the hymenium looking upwards, was laid 

 flat on a sheet of glass in the laboratory. 

 About two seconds thereafter, the piece of 

 fruit-body puffed and the cloud of spores 

 was shot away irom the liymenium in the 

 manner shown : a the basal end and b the 

 apical end of the piece of fruit-body (shown 

 insection); c, the sheet of glass ; thearrows 

 indicate the direction in which the asci dis- 

 charged their spores. Natural size. 



