ASCOMYCETES AND WIND DISPERSAL 



235 



We shall now consider the phenomenon of the separation of 

 the spores from one another, just after discharge from the ascus. 

 That this actually occurs in some and probably in very many 

 species seems to me to be conclusively proved by (1) The definite 

 observation by Falck x that the spores of Gyromitra esculenta 

 settle singly, and a similar observation by myself upon Bulgaria 

 polymorpha ; (2) the just quoted description by Plowright of 

 spore-discharge in Morchella gigas ; 

 and (3) some observations upon ': 



the discharge of individual asci of 

 Peziza which have been made by 

 my laboratory attendant, Mr. C. 

 W., Lowe, and myself. Mr. Lowe 

 has informed me that h& watched 

 the discharge of spores from a 

 fruit-body of Peziza aurantia be- 

 neath an electric lamp with a 

 lens. He states that each indi- 

 vidual ascus jet appeared to break 

 up at a distance of from 2 to 2*5 

 cm. from the top of the fruit-body, 

 and that in one instance on the 

 breaking up of a jet, he was able 

 to count six separated spores. 

 With the help of my beam-of-light method I have fortunately been 

 able to repeat and extend these observations. 



A fruit-body of Peziza repanda (Fig. 77) came up upon horse 

 dung in the laboratory. When ripe, it was placed upright in the 

 middle of a covered glass jar, 6 inches high and 4 inches in 

 diameter ; and a strong beam of light was directed through the 

 air immediately above the hymenium. 2 I then observed that 

 the asci discharged their contents into the air successively, at 

 intervals of a few seconds. Although in the course of two or 

 three hours I watched the discharge of several hundred asci, in 

 no case was I able to detect an ascus jet taking its upward flight 



FIG. 77. The discharge of spores from 

 Peziza repanda, f, section of a fruit- 

 body covered above with the hymenium 

 A and supported by a stipe with a root- 

 ing base ; d, horse dung ; g, glass base 

 of the culture dish. Above the hyme- 

 nium are shown several groups of eight 

 spores as seen in a concentrated beam 

 of light immediately after their dis- 

 charge from the asci. Natural size. 



1 R. Falck, loc. cit. 



2 Cf. Part I., Chap. VII. 



