Humaria rutilans, Fries . 
5i 
The existence of brachymeiosis suggests a new distinction between 
sexual and asexual fusions. The two fusions in the life-history of Humaria 
rutilans are very similar in character ; both are fusions of apparently 
undifferentiated nuclei, and, in both, the nuclei which fuse have often been 
present in the same cell since their formation. Each fusion also results in 
a doubling of the number of chromosomes, and is compensated by a process 
of reduction. 
The first fusion, however, occurs at the same stage in the life-history 
as a normal act of fertilization and initiates a similar development. The 
second fusion takes place after meiosis has begun. The syngamous fusion 
is related here, as in all other investigated organisms to a meiotic reduction. 
The asexual fusion in the ascus is followed by the simpler brachy meiotic 
process, and there is reason to believe that this method of reduction may 
compensate other asexual fusions also. 
Association of Nuclei. 
According to Maire (32, 33) the nuclei in the ascogenous hyphae 
of various Ascomycetes are associated in pairs, and constitute a synkaryon 
comparable to that observed by various authors in the Basidiomycetes. 
I have not been able to observe such an arrangement in H. rutilans . 
Harper (31) also has observed paired nuclei in Phyllactinia y and 
suggests that the fusion in the ascus is to be related to the fusion in the 
teleutospore and basidium, the association of nuclei in pairs having { worked 
back ’ in the latter cases, to the stage of fertilization, and the occurrence of 
two fusions, as in the Ascomycetes, being therefore eliminated. 
As, however, Blackman and others (5, 7, 9) have shown, the nuclear 
union in the teleutospore is a stage in the act of fertilization initiated in the 
aecidium (or at some equivalent point in the mycelium), and corresponds to 
the fusion of the sexual nuclei in other plants and animals, and therefore to 
the fusion which takes place typically in the female organ of Ascomycetes. 
The fusion in the ascus follows the fusion of the sexual nuclei. It 
appears to be a peculiar process intercalated in the life-history of the 
Ascomycetes and is compensated by the third division in the ascus. 
The ascus, however, resembles the teleutospore (or its outgrowth, the 
promycelium) and the basidium in being a spore mother-cell in which 
reducing divisions take place. 
Spore-formation. 
The details of spore-formation were first studied by Harper (26), 
who regards the spore as cut out by astral rays which fuse laterally to 
form a membrane. 
This point, together with its bearing on the phylogeny of the Asco- 
mycetes, has recently received full discussion from Faull (19), who describes 
