HELIOTROPISM OF ASCI IN DISCOMYCETES 289 



damp-chamber (3'5 X 2 x 2*25 feet) kept on a table in the 

 laboratory a few feet away from a window. The dung was watered 

 from time to time to keep it moist. After about a month, on some 

 of the dung-balls, fruit-bodies of Aleuria vesiculosa began to appear. 

 Sometimes they were clustered, at other times sohtary. They 

 were never very large and, owing to the conditions under which 

 they were grown (excessive moisture and relatively feeble light). 



Fig. 138. — Aleuria vesiculosa. Vertical section tlirough a 

 very large fruit-body. Its cupulate form was developed 

 by marginal growth. Tlie liymenium a lines the inside 

 of the fruit-body. The asci in the upper regions of the 

 fruit-body at b and c would be at a disadvantage in dis- 

 charging their spores were they not heliotropic and 

 therefore directed toward the cup's mouth. Outline of 

 the Jruit-body copied by the author from Boudier's 

 Icones Mycologicae, PI. 257, c. Natural size. 



they tended to be abnormal : firstly, in sometimes having a well- 

 pronounced stipe and, secondly, in becoming more expanded than 

 usual (Fig. 167. p. 333). The expansion was due to the paraphyses 

 swelling laterally prior to the discharge of the spores from the 

 asci. 



In Volume I of these Researches I gave an account of the pro- 

 duction and hberation of the spores of the fruit-bodies just described 

 but, unfortunately, misnamed the species Peziza repanda. From 

 a comparison of my fruit-bodies grown in cultures with the fruit- 

 bodies of Aleuria vesiculosa growing in the open, I am now 



VOL. vr. 



