344 RESEARCHES ON FUNGI 



That the four sets of basidia which are present on the hymeniura 

 do really represent four generations was proved by studying the 

 development of the hymenium upon a living gill seen in face view. 

 At one stage of development of one small area of the hymenium, 

 it was found (1) that the spores on the longest basidia were 

 dark brown and therefore fully pigmented, (2) that the spores on 

 the next longest basidia were brownish, (3) that the spores on the 

 next longest basidia were just beginning to become coloured, and 

 (4) that the spores on the shortest basidia were quite colourless. The 

 longest set of basidia, the next longest set, the next longest set still, 

 and the shortest set begin to develop th^ spores at successive inter- 

 vals of time ; and they likewise complete the development of their 

 spores at successive intervals of time. It is clear that the develop- 

 ment of the hymenium of Coprinus micaceus is similar to that of 

 Coprinus sterquilinus, already so fully described, with the difference 

 that in the former species there are four generations of basidia to 

 be considered whereas in the latter there are only two. In Coprinus 

 micaceus the wave of spore-development which passes upwards on 

 each gill is compound ; for, in reality, it is composed of four simpler 

 waves, one for each of the four basidial generations. 



The spores on any small area of the hymenium, when about to 

 be discharged, are all equally dark brown in colour, as is indicated 

 in Fig. 156 (p. 348). However, for the sake of diagrammatic clear- 

 ness, in Fig. 153, B, the spores of the first, second, third, and fourth 

 generations of basidia, respectively, have been uniformly blackened, 

 shaded with crossed lines, shaded with simple parallel lines, and 

 left unshaded. The relative numbers and positions of the basidia 

 of each of the four generations present in Fig. 153, A and B, are 

 made clear by the further analysis embodied in Fig. 154. Here at 

 A, B, C, and D are shown the spores of the first, second, third, and 

 fourth basidial generations respectively. Counting parts of spores 

 at the edges of the drawings as wholes, the number of spores of the 

 first, second, third, and fourth generations are 25, 112, 133, and 187 

 respectively. It thus appears that, proceeding from the first to 

 the last generation on any given area, there is a progressive increase 

 in density of distribution of the basidia. 



The tetramorphism of the basidia of Coprinus micaceus has the 



