ASCOBOLUS. 163 



paraphyses numerous, about 2 p. thick, septate, very variable, 

 clavate or cylindrical at the apex, sometimes inflated below 

 the summit, colourless, but involved upwards in a sulphur- 

 coloured mucilage. 



Peziza stercoraria, Bull., Champ. Fr., t. 376 and 438 ; Sow., 

 Brit. Fung., tab. xviii. 



On cow and horse dung, crowded in patches or scattered. 

 Saccardo states that this species is also met with rarely on 

 dung of deer and cat, also on human dung. 



The present very common species illustrates very clearly 

 some of the peculiarities of the genus Ascobolus. Examina- 

 tion with a good pocket-lens shows, in a mature specimen, 

 the asci containing their dark-coloured spores, projecting 

 above the surface of the hymenium. If a thin section of an 

 ascophore in this stage is placed under the microscope, some 

 quite young asci cylindrical in outline, with the apex yet 

 below the level of the hymenium, and containing perfectly 

 colourless, smooth spores, usually arranged in a single row, 

 will be seen ; other asci will probably be present whose 

 apex has just reached the level of the surface of the hy- 

 meniuin or disc, the upper portion of the asci wider and 

 altogether more clavate than in the younger example pre- 

 viously mentioned, the spores will now be more or less 

 tinged with violet, and present darker streaks extending from 

 end to end, and running into each other ; finally some asci 

 will be seen whose apex stands very much above the level 

 of the hymenium or disc, the projecting portion being 

 broadly club-shaped, and the violet-brown spores irregularly 

 huddled together in this upper swollen portion. If this 

 large projecting ascus is traced downwards, it will be seen 

 that the very much narrowed base is still attached to the 

 hypothecium, the ascus does not become free at the base, 

 but remains fixed, the increase in size being due to expan- 

 sion by the accumulation of water, and is concerned with 

 the dispersion of the spores, and after dehiscence the ascus 

 contracts below the level of the hymenium. 



It would probably be noticed when examining the hyme- 

 nium with a pocket-lens that all the projecting asci were 

 strongly bent in the same direction. This is due to the 

 action of light, the asci being positively heliotropic. This 

 can readily be demonstrated by growing the fungus under 



M 2 



