i8 



RESEARCHES ON FUNGI 



the fruit-body by excreting surplus water. Possibly, when a 

 fruit-body is rather dry and suddenly becomes surrounded with air 

 saturated with water-vapour, the hairs absorb water-vapour from 

 the air and conduct it into the fruit-body. 



The Pilear Flesh. — The flesh of the pileus is bounded externally 

 by a pahsade layer composed of rounded or pear-shaped cells which 

 fit tightly together, and it is divided into strips by grooves (Fig. 16, 

 A, p. 22) which run above the gills from the disc to the pileus- 

 periphery. Owing to the presence of these grooves, a young pileus, 



Fig. 12. — Coprinus curtus. Pilocystidia or pileal hairs. To illustrate their excretory 

 function. Hairs : a, before excretion ; b, a small drop has been excreted ; c, a large 

 drop has been excreted ; d, the drop is drying up, its colloidal nature revealed by its 

 irregular surface ; e and /, further stages in the drying up of a drop ; g, a single 

 hair with a lateral drop ; h, two hairs, with the two drops fused ; i, six hairs, with 

 their drops fused. Magnification, 293. 



just before expansion (Figs. 3, p. 7, and 7, A, p. 13), appears to 

 be longitudinally striate. Similar striae may be observed in the 

 pileus-flesh of unexpanded fruit-bodies of Coprinus plicatilis (Fig. 24, 

 p. 41) and C. micaceus. The grooves facilitate the opening of the 

 pileus in a parasol-like mapner {cf. Fig. 18, p. 27). 



The Gills. — Fully developed gills in large fruit-bodies are 8- 

 10 mm. long and 1-1 • 3 mm. wide in the middle (Fig. 13, A, B, and 

 C) ; in small fruit-bodies they are proportionately smaller ; while 

 in dwarf fruit-bodies, the expanded pilei of which attain a diameter 

 of only 2-5 mm. or even less, they do not exceed 1 mm. in length 

 and a fraction of 1 mm. in width. In a young unexpanded fruit- 

 body, the inner edges of the gills are all joined together ; so that, 



