RESEARCHES ON FUNGI 



is shown in Fig. 109. In many species in which the basidia are 

 normally tetrasterigmatic one may sometimes find a few basidia 

 scattered at rare intervals which are tristerigmatic. Such I have 

 observed for example in several species of Coprinus, e.g. C. niveus 

 (Fig. 110, b), in Panaeolus campanulatus, and in the field forms of 



Psalliota campestris. 



In tristerigmatic basidia 

 the three sterigmata are 

 always placed equidistantly 

 at the top of the basidium. 

 Their positions are like 

 those of the three corners 

 of an equilateral triangle. 



Tetrasterigmatic basidia 

 are the rule in most species 

 of Hymenomycetes. This 

 arrangement is so frequent 

 that there is no need to 

 quote the names of species. 

 Wherever it occurs, the 

 four sterigmata (except in 

 certain Tremellineae) are 

 placed equidistantly on 

 the top of the basidium. 

 Their relative positions are 

 like those of the four 

 corners of a square. 



Pentasterigmatic basidia, 

 according to Patouillard, 1 

 occur in Cantharellus Friesii Q . The illustration given by this author 

 shows a single basidium with five sterigmata and five spores. 

 In Anettaria separata, Coprinus niveus, and some other species 

 of Agaricineae, where the basidia are normally tetrasterigmatic, 

 I have occasionally met with a basidium with five sterigmata 

 (Fig. 110, c). In pentasterigmatic basidia the sterigmata have 

 the same relative positions as the five corners of a regular pentagon. 

 1 N. Patouillard, loc. cit., p. 148. 



FIG. 108. Coprinus narcoticus a Coprinus 

 with a strong and disagreeable odour. 

 Fruit-bodies coming up in a pure culture 

 on horse dung. Species obtained at 

 Winnipeg. Photographed at 6.30 A.M. 

 The opening of the pileus takes place 

 during the night. Natural size. 



