COPRINUS STERQUILINUS 215 



were removed from a fruit-body growing normally in the laboratory 

 and were tested immediately after their removal. On testing the 

 hymenium in a very young stage of its development, when the 

 basidia possessed only bodies but no sterigmata or spores, no trace 

 of glycogen could be found in it : the basidium-bodies and the 

 paraphyses stained yellow with iodine, thus revealing the presence 

 of proteins only. However, in the same preparations there was 

 an abundance of glycogen in the cells of the subhymenium and 

 trama. At a little later stage in the development of the basidia, 

 when the nuclei were about to divide, clumps of glycogen began 

 to appear at the ends of the basidium-bodies, as shown at g in 

 Fig. 89, A (p. 208). Still later, the basidium-bodies became laden 

 with glycogen and showed the reddish-brown reaction with iodine 

 in a very marked degree. At this stage the reddish-brown colour 

 was exhibited by the contents of all the cells of the trama, sub- 

 hymenium, and hymenium, including the paraphyses and basidia. 

 Shortly after attaining full size and while still possessing colourless 

 walls, the spores on the sterigmata stained intensely reddish-brown 

 with iodine, and it was therefore evident that the glycogen in the 

 basidium-bodies was being transferred to the spores. On becoming 

 older, the spores gradually lost their glycogen contents. At first 

 the glycogen was evenly spread throughout the spore-protoplasm ; 

 but, as it was disappearing, it separated into clumps. These clumps 

 became smaller and smaller until, finally, the iodine yielded no 

 trace of them. It thus appears that, in Coprinus sterquilinus, as 

 in other Hymenomycetes and in the Ascomycetes, glycogen is 

 not stored up as a reserve food material in the spores. What 

 becomes of the glycogen in the spores whilst it is disappearing ? 

 It must be transformed into some other chemical substance, possibly 

 another carbohydrate such as trehalose,^ and this is doubtless 

 packed away in the spore so that it may lie in reserve and be drawn 

 upon at the time the germ-tube is developed. An analysis of the 

 contents of ripe spores might solve this problem. From what 

 substance, in the first place, is the glycogen in the gills formed ? 

 Possibly from a fat ^ but, as the facts of chemical analysis are not 

 at our disposal, this supposition is merely speculative. 



1 Cf. Zellner, op. ciL, pp. 116-117. ^ Ibid., p. 117. 



