252 



M. C. COOKE ON NUCLEATED SPORIDIA. 



inner surface, which is the hymeniwm, numerous transparent tubes, 

 or cylindrical sacs, present their upper extremities, whilst their 

 lower ends coalesce with the cellular substance of the cup. These 

 cylindrical bodies are the thecce or asci, mixed with thread-like fila- 

 ments called paraphyses. Sometimes the paraphyses are simple, at 

 others branched, and either attenuated or clavate at their tips. In 

 a few cases the club-like extremities of the paraphyses are coloured, 

 but usually the asci and their contents, as well as the paraphyses, 

 are colourless. In this genus the paraphyses are important features 

 in the determination of species, since they offer considerable varia- 

 tion in different species. What may be their special function has 

 not been satisfactorily determined. Some authors have suggested 

 that they may be barren asci ; but this suggestion is far from con- 

 firmation by fact, no observations having yet traced the develop- 

 ment of paraphyses into asci, or explained why they are so distinct 

 from asci even in the earliest stages at which they can be traced. 

 Similar bodies are also present iu the cups of lichens. The asci in 

 their earliest stages are filled with a granular matter, which ulti- 

 mately is collected (normally) into eight spherical, elliptical, or 

 elongated sporidia, which fill the ascus, and when mature are dis- 

 charged by rupture at the apex, in little puffy clouds of sporidia, 

 as already intimated. 



It was for some time a matter of concern with me how to mount 

 and preserve these delicate sections of Peziza, so that they should 

 retain their form unchanged for examination and comparison 

 throughout any period of time. The watery character of these 

 fleshy fungi is one great obstacle to the employment of balsam as a 

 medium, and specimens so mounted are mere caricatures of their 

 originals. Many difficulties beset objects mounted in fluid, and 

 glycerine has not been a great favourite for such a purpose. 

 Latterly, however, I have found nothing better than pure glycerine 

 employed in the following manner. The fragment of Peziza is 

 placed on a slide in a drop of glycerine (diluted glycerine is a mis- 

 take, the purer the glycerine the better), then cover with thin glass, 

 three-quarter inch square, press firmly and hold it in position with 

 a wire clip. Blotting paper removes all extraneous glycerine which 

 is pressed out from beneath the cover, or if not quite clean, a camel 

 hair pencil and water will complete the cleansing. In the next 

 stage of the process the edge of the cover is painted round with 

 gum dammar dissolved in benzole. This solution is more inde- 



