48 



RESEARCHES ON FUNGI 



be 4-29 mm. per second.^ In most Hymenomycetes, the rate of 

 fall of the spores under similar conditions is much less than this. 

 In Psalliota campestris, for example, it is only about 1-5 mm. per 

 second.^ The high rate of fall of the spores of C. plicatilis is doubt- 

 less due in part to their large size and in part to their high specific 

 gravity which was determined to be approximately 1-21.3 



The Stipe. — The stipe is very slender, fragile, smooth, hollow, 

 greyish tinged with white or brown, and varying in height from 

 3 to 9 cm. Fruit-bodies with relatively short stipes were found on 

 exposed well-hghted lawns and in well-cropped meadows, while 



o 



1: 



^ 





Fig. 32. — Coprinus plicatilis. Variations in size and shape of average spores 

 of three different fruit-bodies taken from the same lawn at Birmingham, 

 England: A in 1906, Bin 1910, and C in 1911. A, front view, side view, 

 and end view of an average spore (1906 fruit-body). B, similar views 

 (1910 fruit-body). C, two front views and one end view of average 

 spores (1911 fruit-body). Magnification, 1333. 



fruit-bodies with relatively longer stipes were found under trees in 

 damp and shady places. The base of each stipe is swollen. The 

 shaft tapers upwards very shghtly : it is usually 1 • 5-2 mm. thick 

 above the swelling and about 1 mm. thick just below the pileus. 

 Small pilei are borne on thinner stipes than large pilei. However, 

 there is no uniform correlation between the width of an expanded 

 pileus and the height of the stipe. Thus, the widths of the pilei 

 of three fruit-bodies were 12 mm., 15-5 mm., and 39 mm., and the 

 heights of the stipes 5-4 cm., 9 cm., and 5-5 cm. respectively. 



Just before and during the expansion of the pileus, the apex of 

 the stipe is very sensitive to the stimulus of gravity ; and, when a 

 fruit-body with an upright stipe at this stage of development is 



1 These Researches, vol. i, 1909, p. 175. ^ /^j^.^ cf. p. 180. ^ j^^^^ p, 154, 



