580 Wager . — The Sexuality of the Fungi. 
also contains a smaller quantity of stainable substance. The 
male nucleus increases in size until it attains the same size 
and staining properties as the female nucleus, and in this 
condition the zygote enters on a resting stage. Fusion does 
not definitely take place until germination begins, and in all 
cases where it has been seen, it occurs not in the zygote 
itself, but in the young sporangium which is at once formed 
when the zygote begins to germinate h 
In the Mucorineae the zygotes are formed by the fusion of 
multinucleate cells (apocytia), which are, so far as can be 
seen, identical with one another. The investigations of 
Dangeard and Maurice Leger 1 2 on Sporodinia grandis show 
that the sexual cells are distinctly isogamous and contain 
several hundreds of minute nuclei On fusion taking place 
the protoplasm and nuclei of the two cells become mixed 
together. Changes then take place leading to the dis- 
appearance of all the nuclei. At the same time two groups 
of deeply stained bodies appear, one at each end of the 
zygote. According to Leger 3 each group is composed of 
from fifteen to thirty small spheres (nucleoli ?), ‘ spheres 
embryogenes.’ They arrange themselves into a spherical 
layer surrounding a globule of oil and then fuse together, 
producing a hollow sphere, ‘ sphere embryonnaire,’ full of oil. 
In the process of germination these two ‘ spheres embryon- 
naires ’ increase in size and fuse together. The fused mass 
becomes clear, and numerous nuclei appear in it, which 
pass into the sporangiferous mycelium and begin to divide. 
The same phenomenon is observed in the azygospores, except 
that only one sphere is produced. 
The union of the ‘ spheres embryogenes * is the sexual 
process. The azygospores are therefore truly sexual, and 
1 These observations are taken from an unpublished paper by the writer. See 
also Brit. Ass. Reports, 1898, p. 1064. 
2 Dangeard and Maurice Leger, (1) Recherches sur la Structure des Mucorinees ; 
(2) La Reproduction sexuelle des Mucorinees. Le Botaniste, vol. iv, 1894-5, 
pp. 4 and 7. 
3 Leger, Structure et developpement de la zygospore du Sporodinia grandis. 
Revue g^nerale de Botanique, t. vii, 1S95, p. 481. 
