322 RESEARCHES ON FUNGI 



trial of different arrangements. In Coprinus echinosporus, there- 

 fore, the basidia mutually influence one another in the arrange- 

 ment of their sterigmata so that in the end the most economical 

 arrangement tends to be established. In Panaeolus campanulatus 

 I have not been able to observe any tendency toward the domino- 

 eight arrangement. 



Whilst I have not been able to convince myself that in Panaeolus 

 campanulatus adjacent basidia influence each other in respect to 

 the places of origin of their sterigmata, yet, when two or more 

 basidia are unusually crowded, it is evident that they accommodate 

 themselves to one another by a suitable bending of the sterigmata. 

 Evidence of this phenomenon is afforded by the eight camera- 

 lucida drawings given in Fig. 112. At H are shown three basidia. 

 The middle one, which is the youngest, is crowded in between 

 the two others. Its two lateral spores are drawn together and 

 its other spores are separated by more than the normal distance. 

 The position of these four spores is determined by the bending 

 of the sterigmata. One can at once perceive that the middle 

 basidium has beautifully adapted itself to its crowded position. 

 Had its sterigmata had their usual direction, so that the spores 

 would have been at the corners of a square, actual contact of at 

 least one of the spores with the spores of one of the neighbouring 

 basidia would have taken place. 



The bending of the four sterigmata, so that one pair is drawn 

 nearer together and the other pair becomes more divergent, results 

 in a rhomboidal arrangement of the four spores when these are seen 

 from above. From the various drawings in Fig. 112, it becomes 

 evident that the rhomboidal arrangement is adopted only under 

 conditions of crowding, and in such a way as to allow of the spores 

 of any basidium affected being situated more favourably as regards 

 space among the spores of the surrounding basidia. In Fig. 112 

 at A, D, and F, the rhomboidal arrangement comes out clearly 

 in groups of mature basidia. At A, its adoption results in larger 

 spaces being placed between the spores of several pairs of adjacent 

 basidia. At D and F, where the necessity for the rhomboidal 

 arrangement is very great, this arrangement is very marked indeed ; 

 but, at D, it has not been quite sufficient to prevent the rare 



