250 RESEARCHES ON FUNGI 



spore-deposit in front of the hymenium.^ The eight spores of any 

 one ascus come to rest at a distance of about 1 mm. from the 

 hymenium, but the discharges of neighbouring asci set up momentary 

 currents which gradually carry these eight spores farther from the 

 hymenium, and thus the final spore-deposit comes to be situated at 

 a distance of 1-2 mm. from the hymenium. If one examines the 

 exploded and empty asci, one observes : (1) that their openings are 

 all obUquely situated, as shown in Fig. 120, B, and look in the direc- 

 tion in which the spores have been shot ; and (2) that their opercula 

 are all hinged on that edge of the opening which is toward the ascus- 

 base (Fig. 120, B). 



Radial-longitudinal Sections and Surface Views of the Hyme- 

 nium. — The key to understanding the fruit-body of Sarcoscypha 

 protracta as an organ for the production and Uberation of spores is a 

 thorough study of the hymenium in radial-longitudinal sections and 

 in surface views. Only by such a study can one obtain satisfactory 

 evidence of the spatial relations of the asci and paraphyses, and of 

 the relation of the asci with the mouth of the apothecium. Hitherto, 

 so far as I know, no one has ever studied Discomycetes in this way, 

 so that Figs. 1 20, 121, and 1 22 af e the first of their kind in mycological 

 hterature. 



A radial-longitudinal section of an apothecium is, of course, one 

 which, if continued, would pass through the apothecium's longi- 

 tudinal axis ; and, if complete, it would resemble the section shown 

 in Fig. 118 (p. 243). Pieces from each side of such a section are 

 shown in Fig. 120, but, for convenience of illustration, the two pieces 

 have been brought nearer together than they would usually be in an 

 actual section. At A is shown the appearance of the hymenium 

 just before puffing and at B the appearance of the same hymenium 

 one second after puffing. 



In Fig. 120, A, the following points may be observed : (1) the 

 only elements in the hymenium are asci and paraphyses ; (2) ad- 

 jacent asci which He nearly or exactly in the same vertical plane 

 are separated by relatively thick masses of paraphysal branches ; 



1 For a discussion of the mode of action of iodine and of other poisonous sub- 

 stances in causing the explosion of ripe and nearly ripe asci of Aleuria vesiculosa 

 (there misnamed Peziza repanda) vide these Researches, Vol. I, 1909, pp. 238-240. 



