248 Carruthers . — Contributions to the Cytology of 
the ascus, the first two divisions constituting a typical meiosis, and the third 
brachymeiosis of the type described for H. rutilans . 
These results have been questioned by Guillermond, who doubts the 
existence of brachymeiosis. The numerical change in the third division 
has, however, been recorded, not only by those who accept the occurrence of 
two successive fusions, but by an observer so little predisposed in its favour 
as Dangeard (2), who considers that the fusion in the ascus alone takes 
place. 
The essential phenomena in Helvetia show a strong resemblance to 
those in Humaria rutilans. In both the normal sexual process is replaced 
by a fusion of vegetative nuclei, and in both meiosis and brachymeiosis 
occur in the ascus. 
There are, however, differences which are of some interest. In Humaria 
the meiotic phase is initiated before the second fusion, and in the resulting 
nucleus the component nuclei cannot be distinguished. Helvella exhibits 
a less complete fusion, for the two nuclei in the penultimate cell of the 
ascogenous hypha show no sign of the coming meiosis, unless the casting 
out of a part of the nucleolus, the basis of the chromatin body, be regarded 
as a part of the process. 
The association of nuclei in the asexual fusion in Helvella is less 
intimate than in any form yet described. The fusion is at first merely 
a disappearance of the boundary between two nuclear areas, and during the 
initial stages of meiosis there is no mingling of the chromatin. The first 
contraction takes place independently in the two masses of chromatin, and 
it is not until the formation of the spireme that the chromatin threads 
of the original nuclei cease to be distinct. 
It may be possible to correlate this state of affairs with the fact that no 
pairing of the chromosomes takes place in brachymeiosis. 
In Humaria rutilans pairing of the brachymeiotic chromosomes is also 
absent. In this case, although the chromatin masses do not as a rule 
remain obviously distinct, the first contraction is passed through before 
fusion, a fact which seems to indicate that the fusion itself is incomplete. 
Instances were also observed in Humaria in which the chromatin was 
visible in two separate masses in the post-synaptic stage. 
There are four times the post-meiotic number of chromosomes in the 
definitive nucleus of the ascus, but as the first division is heterotype the 
chromosomes are paired before they appear on the spindle, and the quad- 
ruple number is therefore never seen. 
Meiosis. 
The details of meiosis conform to the method described by Farmer and 
Moore in 1905 (5). Two contractions occur, and while there is no evidence 
whatever of an approximation of spiremes, all the observed facts fall readily 
