330 



RESEARCHES ON FUNGI 



the top. She set this cylinder in a stairway, upright, over a culture 

 bearing mature fruit-bodies about to discharge their projectiles ; 

 and then, since light exercises a favourable influence on discharge, 

 she illuminated the culture by placing on one side of it a 100- Watt 

 electric globe and reflector. Since the fruit-bodies of Sphaerobolus 

 are heliotropic only when very young and not at all when nearly 

 mature, the unilateral illumination of the cultures used in the 

 experiments did not affect the direction in which the fruit-bodies 

 shot away their projectiles. The cultures were kept in an east 

 window exposed to daylight until just before they were used for 

 experiment. The projectiles stuck where they struck and hence 

 it was possible to determine the height to which they had been shot 

 in the cylinder. Miss Walker's observations are embodied in the 

 accompanying Table. 



Vertical Range of Sphaerobolus Guns. 



As will be seen by reference to the Table, a great many pro- 

 jectiles struck the lower part of the cylinder. This was doubtless 

 chiefly due to the fact that the fruit-bodies concerned pointed 

 somewhat laterally instead of vertically upwards. 



The greatest height of discharge observed by Miss Walker was 

 4 metres 40 cm. (nearly 14- 5 feet) for Sjihaerobolus stellatus, which for 

 the present is a world record in fungus gunnery. This height is 

 almost twice that observed by me (7-7 feet) with 8. stellatus of 

 Kenora origin. Possibly Miss Walker's fruit-bodies grown on dung 



