HELIOTROPISM OF ASCI IN DISCOMYCETES 307 



toward the mouth of the cup, i.e. toward the source of light. There 

 can be but little doubt that this arrangement of the asci was due to 

 these organs reacting heliotropically during their development. 



A piece of a fruit-body taken from the side of a cup, including 

 a portion of the rim, was laid flat on a slide and its hymenium was 

 examined in face view with the microscope. The overlapping of the 

 ends of the asci as they pointed in the general direction of the rim 

 of the cup could be readily seen 

 (Fig. 148). 



A fruit-body had been kept 

 in a small closed vessel all 

 night. In the morning this 

 vessel was suddenly opened and 

 a piece of the side of the fruit- 

 body was quickly cut away, 

 removed to the outer air of the 

 laboratory, and held horizon- 

 tally with the hymenium 

 looking upwards. Immediately 

 after this had been accom- 

 plished, the fruit-body puffed ; 

 and it was then observed by 

 both Mr. T. C. Vanterpool and 

 myself that the cloud of spores 

 emitted from the hymenium 



was not shot vertically upwards but obliquely upwards at an angle 

 of about 45° toward the rim of the piece of fungus (Fig. 149). 

 This direction of pufhng was, of course, due to the fact that the 

 asci had curved toward the mouth of the fruit-body and were 

 therefore inclined toward the nearest point of the fruit-body's 

 rim. It may be added that the cloud of spores was seen to travel 

 obliquely forward for about an inch and that its emission was audible. 



Puffing of the fruit-bodies of Galactinia badia takes place not 

 only after confinement in a laboratory but also in the open. In an 

 excursion in Kew Gardens Miss E. M. Wakefield and I found some 

 large brown fruit-bodies of 0. badia amid grass under some young 

 trees. I picked one of the fruit-bodies from the ground and 



Fig. 148. — Galactinia badia. Semi-dia- 

 grammatic surface view of hymenium 

 on the side of, and near the top of, a 

 cup-shaped fruit-body (cf. Fig. 146). 

 Asci a and paraphyses b turned up- 

 wards so as to point to the source of 

 strongest light and, therefore, to the 

 fruit-body's mouth. Magnification, 

 345. 



