COPRINUS CURTUS 



21 





exceed the other tramal cells m size, giant tramol cells. When a 

 pileus is expanding, they are the largest cells in the whole fruit- 

 body. The length and breadth of four of the largest were as follows : 

 60 X 56 fi, 55 X 55 fx, 62 X 30 fi, and 60 X 35 fi. The growth in 

 size of the giant tramal cells may 

 be realised by comparing Fig. 16, 

 A, d, which shows them in a crosS' 

 section of a gill taken at 7.30 p.m. 

 in the evening before the morn- 

 ing of pilear expansion, with 



(1) Fig. 16, B, a, which shows 

 them in a similar section taken 

 in the morning during the ex- 

 pansion of the pileus, and with 



(2) Fig. 16, C, a and b, which 

 shows them in the sulcations of 

 an expanded pileus, the pileus be- 

 ing viewed from above. Swollen 

 giant tramal cells are also shown 

 in the sulcations of the gills 

 represented in Fig. 19 (p. 30). 



The Spores. — The spores are 

 black in the mass, dark brownish 

 to black under the microscope, 

 smooth, elliptical, 9-15 x 6-9 /u. 

 (Fig. 17). As may be seen by 

 examining the hymenium in face 

 view (Figs. 14, A, and 15, A), each 

 spore, in reference to the axis of 

 the basidium, is slightly broader 

 in the tangential direction than in the radial. In this respect the 

 spores of Coprinus curtus resemble those of C. micaceus,^ C. niveus, 

 a,ndC.plicatilis,^ but differ from those of C. coma^M*,^ C. sterquilinus* 

 C. atramentarius,^ C. lagopus,^ and most of the other Coprini. 



1 These Researches, vol. iii, 1924, pp. 343-348, Figs. 153-156. 



2 Vide infra. 3 These Researches, vol. iii, p. 153, Fig. 60. 



* Ibid., p. 202, Fig. 86. ^ j^^^ p 281, Fig. 120. ^ if,i^^ p 321^ pig, 142. 



Fig. 15. — Coprinus curtus. The free 

 edge of a gill bearing ripe spores, 

 just before the beginning of the 

 spore-discharge period. A, in 

 surface view ; B, in cross-section : 

 I, long basidia ; s, short basidia ; 

 p, paraphyses ; t, the trama ; 

 m, sterile cells at the extreme 

 gill-edge. Magnification, 293. 



