COPRINUS CURTUS 



15 



foxy-red to the naked eye the proportion of brown cells is high. 

 The degree of redness in the pilear scales varies considerably in 

 different fruit-bodies. Pale scales are very inconspicuous, and on 

 account of their lack of colour 

 and minute size cannot be dis- 

 tinguished with certainty in 

 photographs, e.g. those repro- 

 duced in Figs. 2, 3, 4, and 5 

 (pp. 5, 7, 8, and 10). Deep 

 red scales are at once apparent 

 to the naked eye and, in a 

 photograph, e.g. that shown in 

 Fig. 8, they stand out as black 

 dots. When a transverse section 

 is taken through a pileus on 

 the day before its expansion 

 (Fig. 9), one observes that the 

 brownest cells of each scale are 

 the outermost ones and that 

 all the inner scale-cells are 

 colourless. The walls of a few 

 of the very brownest and 

 outermost cells are sometimes 

 roughened by the presence upon 

 them of a few irregularly placed 

 crystals of calcium oxalate (Fig. 

 9, C, E, and F). However, in 

 general, the walls of the scale- 

 cells are quite smooth and they 

 are never ornamented with 

 minute evenly arranged calcium- 

 oxalate crystals, so that in this 

 respect they differ in a marked manner from the walls of the 

 corresponding spherical cells which form the meal on the pilei of 

 Coprinus stercorarius and C. narcoticus. 



The pilocystidia, of which there are many hundreds on each 

 pileus (Fig. 10), spring from cells which form part of the universal 



Fig. 9. — Coprinus curtus. Transverse 

 sections ttirough the reddisli or white 

 scales on the surface of the pileus. 

 A, the fruit-body investigated. B, 

 the scale s is lying over the palisade 

 cells p above a gill. C, a scale show- 

 ing contents of cells : a and c, cells 

 containing dark-brown protoplasm ; 

 b, a yellowish cell ; d, colourless cells ; 

 a and b each bear a few crystals of 

 calcium oxalate on their exterior ; e, 

 a young hair growing apically, not 

 yet capitate. D, a scale resting on 

 the pileus-flesh : a, yellow and brown 

 cells which have arisen by budding; 

 b, colourless scale-cells ; c, a full- 

 grown capitate hair (pilocystidium) ; 

 p, palisade cells of the subjacent 

 pileus-flesh. E, a large, very brown 

 scale-cell springing from a colourless 

 cell, its protoplasmic contents are 

 thick and dark-brown. F, a yellow 

 scale-cell. Both E and F bear 

 crystals of calcium-oxalate, some of 

 which in F appeared to be in the 

 vacuole. Magnification, 293. 



