597 
Wager . — The Sexuality of the Fungi . 
of the chromosomes is stated to take place on the germination 
of the zygote in the Peronosporeae (Berlese). 
4. Before fusion the two nuclei, which at first may differ 
very much in size ( Polyphagus ), attain the same size and 
staining properties. 
5. Fusion may take place at once, or may be delayed until 
after germination has taken place ( Basidiobolus , Polyphagus ), 
sp that apparently the formation of the oospore membranes 
and the early stage of germination are independent of nuclear 
fusion. 
6. The fusion of nuclei takes place in the resting condition 
( Cystopus Candidas , P . parasitica, Basidiobolus), or possibly, in 
some cases, in the chromosome stage (species of Cystopus and 
Peronospora (Berlese), Polyphagus { Wager) ). 
7. The formation of sexual organs depends to some extent 
upon the conditions under which the Fungus is grown. 
8. Centrosomes have not been observed taking part in the 
process of fertilization. Definite centrosomes have not been 
observed in the Phycomycetes. 
9. The sexual elements which fuse together in any given 
case are generally derived from one and the same individual, 
often from the same filament ; and in Basidiobolus the two 
nuclei which fuse are derived from adjacent uninucleate cells. 
10. In the higher Fungi nuclear fusions occur at a definite 
stage in the life cycle, resulting in the production of spores 
either directly ( Ustilagineae and Uredineae) or indirectly 
(Ascomycetes and Basidiomycetes). 
11. These nuclear fusions are probably not morphologically 
sexual, but they replace the sexual act, and are physiologically 
equivalent to it, in that the cell is thereby reinvigorated to 
further development, and this accounts for the continued 
asexual reproduction of these forms. 
12. Among the higher P'ungi the simpler Ascomycetes 
only, such as Sphaerotheca , exhibit a true sexual fusion, 
accompanied, however, by a subsequent fusion of nuclei in 
the ascus. 
R r 2 
