INHIBITORY EFFECT OF LIGHT 105 



The cultures were prepared for the experiments in the following 

 manner. Fresh dung-balls were fetched from a stable. For the 



Fig. 58. — Coprinus sterquilinus. To show the position of the base of a fruit- 

 body in relation to horse-dung balls in a top-lighted pure culture. A 

 fruit-body arose in a dark crevice below a dung-ball and began to push 

 upwards. When 2 cm. high, its pileus was removed by cutting the stipe 

 across just below the pileus and then a new pileus, cutoff from another 

 fruit-body in the same way, was substituted for the first (c/. Fig. 25, 

 A-D, p. 79 in Vol. II). The graft attached itself to the stock and grew 

 vigorously as indicated by the photograph. The compound fruit-body, 

 which has grown in tlie same manner as any ordinary fruit-body, is well 

 fixed to its substratum owing to pressure by the dish and the base of the 

 dung-ball under which it originated. Winnipeg material. Natural size. 



first three cultures large dishes were employed (6-7 cm. high and 

 18-21 cm. wide). In these the balls were placed and packed closely 

 together so that the spaces between them where they came into 



