320 



RESEARCHES ON FUNGI 



Octosterigmatic basidia occur in some of the Thelephoraceae, 

 e.g. Corticium coronatum (Schrot.) v. H. et L. Here, according to 

 von Hohnel and Litschauer, 1 almost always, eight sterigmata are 

 present on each basidium. I myself have seen octosterigmatic 

 basidia in one of the species of Corticium. 

 ^ n octosterigmatic basidia the sterigmata 

 on the top of the basidium have the 

 same relative positions as the corners of 

 a regular octagon. 



So far as I am aware, there are no 

 species of Hymenomycetes in which the 

 normal number of sterigmata on each 

 basidium is nine, ten, or any regular 

 number greater than eight. 



From the foregoing, we have seen 

 that, at their origin on the top of a 

 single basidium, the sterigmata appear to 

 repel one another with equal strength, 

 so that in the end the spaces separating 

 adjacent sterigmata are all equal. We 

 may therefore state the following law 

 with regard to the position of sterigmata 

 on any one basidium : When only one 

 sterigma is present, it occupies a median 

 position on the top of the basidium-body ; 

 when more than one sterigma are present, 

 the sterigmata arise in such positions on 

 the top of the basidium-body that they are 

 as remote from one another as possible. 



From the observations of cytologists 2 it appears that the nuclei 

 derived from the fusion-nucleus in the basidium attach themselves 

 by means of their centrosomes to those parts of the basidial wall 

 which are to bulge upwards and develop into sterigmata. We 



1 F. von Hohnel und V. Litschauer, loc. cit., p. 94. 



2 E.g. M. Levine, " Studies in the Cytology of the Hymenomycetes, especially 

 the Boleti," Bull. Torrey Bot. Club, vol. xl, 1913, pp. 172-173. For reference 

 to the papers of Rene Maire and R. E. Fries, vide infra, Chap. XIII. 



Fia. 110. Coprinus niveus. 

 Teratology of basidia and 

 spores, a, a normal tetra- 

 sterigmatic basidium ; 6, 

 a tristerigmatic basidium ; 

 c, a pentasterigmatic basi- 

 dium ; d, a normal spore 

 seen from in front and 

 sideways ; e, f, and g, 

 spores showing progres- 

 sively deep bifurcation ; 

 h, a small spore showing 

 bifurcation ; i, j, and k, 

 spores showing progres- 

 sively asymmetrical bifur- 

 cation ; I, an irregularly 

 shaped spore ; m, two 

 very small black spores, 

 one showing a bifurcation. 

 Magnification : a, b, and 

 c, 293 ; d-m, 707. 



