7 2 RESEARCHES ON FUNGI 



would show that the latent period for the fungus stipes is quite as 

 short, if not shorter, than that for roots. 



Already, in describing the adjustments of Coprinus plicatilis, 

 we have become acquainted with the fact that a stipe which has 

 been displaced from a vertical position performs a series of geo- 

 tropic oscillations before again coming to rest. A similar pheno- 

 menon occurs with Coprinus plicatiloides, but in this species the 

 oscillations sometimes take place in surprisingly short intervals of 

 time. In one experiment a fruit-body was 

 moved from a vertical to a horizontal posi- 

 tion whilst the stipe was rapidly growing in 

 length (Fig. 27, a). The plane of the base 

 of the pileus became turned upwards through 

 a right angle in 1 hour and 15 minutes (b). 

 However, the curvature of the stipe was con- 

 tinued for half-an-hour until the pileus plane 

 had become tilted up to a maximum angle 

 of 41° (c). The stipe then began to make a 

 Fig. 27.— Geotropic reaction reverse curvature, and in the course of an 



of the stipe of Coprinus , , . 1r in • -i • 



plicatiloides. The fruit- hour and a halt gradually regained its ver- 

 a^rtSito'T'holoS «^1 Portion. Its oscillatory movements 

 position, a. b-d, subse- then ceased. The pileus, which at this stage 



quent positions of the . ° 



fruit-body : b, after i hr. had already become partially expanded, then 



15 mins.; c, after 1 hr. i -^ u? . • i • i. i i i 



45 mins. ; d, after about spread itself out in a horizontal plane and 

 3 hrs. 15 mins. The tilt liberated its spores (d). It seems somewhat 



of the plane of the base L v ' 



of the pileus, shown at c, remarkable that, in the attempt to bring the 



was 41°. Natural size. ., . . . ..„.., 



pileus into its optimum position for liberat- 

 ing the spores, although the first geotropic reaction was so remark- 

 ably overdone, the second should have resulted in such complete 

 success. The second adjustment was accompanied by, and probably 

 affected by, the opening of the pileus. 



The most interesting case of geotropic oscillations was observed 

 with the already mentioned very sensitive fruit-body which turned 

 upwards through a right angle in 17*5 minutes after displacement. 

 The stipe executed no less than five oscillations about its normal 

 position (Fig. 28). The successive geotropic supracurvatures were 

 28°, 8°, 3°, 1°, and 0°. The swing past the normal position in each 



