470 Fraser and Welsford . — Further Contributions to the 
We have observed eight chromosomes in the ascogenous hyphae, and 
also, like Guillermond, throughout the first division in the ascus. We 
regard eight, therefore, as double the postmeiotic number, produced either 
(in the ascogenous hyphae) by a pseudapogamous fusion alone, or (in the 
ascus) by an additional fusion combined with meiotic reduction. 
In the second and third divisions we find four chromosomes throughout. 
It seems to us, therefore, that brachymeiosis takes place, as in Humctria 
rutilcms and Otidea aurantia , in the third division in the ascus, but that, 
just as in Otidea the chromosomes unite in the third prophase, so here 
they are paired during the prophases of the previous division. If this 
union were somewhat deferred, Maire’s eight chromatin masses would of 
course appear, fusing later to form four ; and if, as in Humaria rutilans , 
it were altogether omitted the eight chromosomes of Guillermond would 
be observed throughout the second division and in the third prophase. 
It is to be regretted, however, that neither author figures all the stages 
he describes. 
Maire (20) and Guillermond (14) have also investigated Galactinia 
succosa. Here they each find four chromosomes on the heterotype spindle 
preceded by a varying number of protochromosomes. In the early anaphase 
they find four chromosomes passing to each pole, but in the late anaphase 
eight are present. Eight also appear in the second prophase and unite 
on the spindle to form four. Four were observed in the second anaphase 
and throughout the third division. 1 
From the observations detailed above, the following points seem to us 
to emerge : — 
(1) In Humaria rutilans there is no obvious mechanism for the 
separation of allelomorphs in brachymeiosis. 
(2) In Otidea aurantia such a mechanism is apparent, the chromosomes 
uniting in pairs during the brachymeiotic prophase. 
(3) In Peziza vesiculosa the time of the corresponding union seems 
to be variable ; it took place in our material during the early stages of the 
division which precedes brachymeiosis. 
(4) In Galactinia succosa pairing is brought about on the spindle of 
the first division, but it is very unstable, the four chromosomes separating 
into eight from time to time. 
(5) In Phyllactinia corylea the chromosomes pair immediately after 
the nuclear union in the ascus, and the same is the case with regard to 
sexual fusion. 
1 Another case of great interest is that of Morchella esculenta , where Maire (20), after observing 
eight chromatin bodies in the prophase of the first division in the ascus, finds four in the metaphase 
and anaphase of the third, and also in the division of the spore nuclei . This, so far as we are aware, 
is the only instance in which the chromosomes have been counted between brachymeiosis and 
fertilization. Unfortunately the species has not been fully investigated. 
