50 Fraser . — Contributio 7 is to the Cytology of 
bodies pass to each pole ; in the second and third anaphases only four can 
be distinguished. It may perhaps be possible that these eight bodies are 
not, as suggested by Maire, protochromosomes, but rather true chromo- 
somes, which become associated in pairs during a part of first and second 
mitoses, as is the case throughout these divisions in Phyllactinia. The 
four bodies which pass to the poles in the third division would be, 
as in both Phyllactinia and Hum aria, the univalent, postmeiotic 
chromosomes. 
It must be added that Guillermond (.25) finds eight chromosomes 
throughout theascus divisions in P. vesiculosa . Possibly, then, the grouping 
of the chromosomes in pairs does not always take place ; such an hypothesis 
would account for the discordant results obtained by Maire and Guillermond. 
It seems not improbable, on the analogy of the present researches, that the 
eight structures counted by Guillermond in the third telophase represent 
only four chromosomes. 
In Galactinia succosa Maire describes the association of the chromo- 
somes as lasting rather longer than in P. vesiculosa ; this species, therefore, 
shows a state of affairs in closer accordance with that obtaining in 
Phyllactinia. 
In Phyllactinia , if Harper’s suggestions and those set forth above 
be correct, it seems probable that the constituents of a given double chromo- 
some will pass to different nuclei, and it may be that their association in 
pairs is a provision to ensure that end. A similar provision then is evident 
in G. succosa and P. vesiculosa , and it is likely that it exists in Humaria 
rutilans , although in this case it is not apparent. If this be so, a sorting of 
the chromosomes, analogous to that which occurs in the meiotic phase, 
would appear to take place in the third division in the ascus. 
This division represents a type of reduction differing markedly from 
the meiotic phase, and to which the term brachymeiosis may be con- 
veniently applied. It shows none of the characteristic features of meiotic 
reduction, it takes place in a single mitosis, and it is not preceded by 
a contraction of the nuclear material. 
The absence of this contraction probably entails the most essential 
distinction between meiosis and brachymeiosis. Meiosis, while it brings 
about the separation of entire somatic chromosomes, yet, in its contraction, 
presumably allows a mingling of maternal and paternal chromatin. In 
brachymeiosis such a contraction does not appear, and the separation 
of entire chromosomes alone takes place. It is thus to be expected that 
the product of a brachymeiotic division should follow very exactly the law 
of Mendel allowing none of the minor variations which meiosis makes 
possible. On the other hand it is quite likely that in brachymeiosis the 
e7ttire nuclei which united in asexual fusion separate from each other, and 
that no interchange of chromosomes takes place. 
