586 Wager . — The Sexuality of the Fungi . 
belonging to the orders Hymenomycetes, Tremellineae, and 
Auricularieae. 
The number of nuclei which fuse together appears to vary 
in the different species. In Stropharia stercoraria x two or 
more ; in Amanita muse aria 2 two or three ; in Mycena galeri- 
culata 3 four, and in Lepiota mucida 4 six to eight. Dangeard 5 , 
however, who has extended his researches to species of 
Dacryomyces , Calocera , Craterellus , Bovista , Nyctalis , Hydnum , 
and Polyporus , states that the young basidium only contains 
two nuclei. In all these cases the nuclei appear to pass into 
the basidium from the hymenium, but Rosen comes to the 
conclusion, from an examination of Psalliota campestris , that 
they may be produced in the basidium. 
The details of the nuclear fusion have been observed in 
Stropharia stercoraria 6 . The two nuclei come into contact 
with one another, and a flattening of each takes place where 
they touch. A dumb-bell-shaped structure is thus produced. 
The membrane separating them then disappears, and the 
nuclear network of the one becomes intermingled with that of 
the other. The fused nucleus is at first oval in shape, and 
the two nucleoli for a short time remain separate, but they 
ultimately fuse together into a slightly elongated mass, which 
soon becomes spherical, and the nucleus then exhibits no 
trace of its composite structure. The single basidium-nucleus 
then divides by mitosis, and the daughter nuclei formed pass 
through the sterigmata into the spores 7 . The fusion of two 
nuclei has been observed mTremella mesenterica by Dangeard 8 , 
and in Auricular ia by Sappin-Trouffy 9 . In both cases the 
1 Wager, Annals of Botany, 1892, p. 146, and 1893, p. 489. 
2 Wager, ibid., 1894, p. 321. 
3 Rosen, Beitrage zur Kenntniss der Pflanzenzellen, ii. Cohn’s Beitr. zur Biol, 
d. Pflanzen, vi, 1892-3, p. 237. 
4 Wager, loc. cit., 1893, p 321. 
5 Dangeard, Sur la Reproduction sexuelle des Basidiomycetes. Le Botaniste, iv, 
1894-5, p. 1 19. 
6 Wager, loc. cit., p. 496 (1893). 
7 Rosenvinge, Sur les noyaux des Hymenomycetes, Ann. d. Sci. Nat., Bot., 
ser. vii, tome 3, 1886. 
8 Dangeard, loc. cit., p. 125. 
9 Sappin-Trouffy, Recherches mycologiques. Le Botaniste, v, 1895-6, p. 44. 
