35 ^ Fraser — On the Sexuality and Development of 
ceeds, become blackened and disintegrated (Fig. 19), and finally it also is 
lost. At a much earlier stage the antheridium has been obliterated. 
The asci develop at the ends of the ascogenous hyphae by the 
peculiar process of bending over (Figs. 20, 21) observed by Dangeard (7), 
Harper (15), and others. In the penultimate cell two nuclei fuse (Fig. 22) 
to form the nucleus of the growing ascus. 
The further development of the asci was not specially studied as the 
object did not appear favourable. Their divisions show an intra-nuclear 
spindle, and finally eight spores are formed in each. 
The peridium never closes completely, as in Humaria , or Ascobolus , 
across the top of the ascocarp, but forms a cup-shaped investment. Within 
is a tangle of vegetative hyphae, amongst which the branches of the 
ascogonium ramify, and from which the paraphyses eventually grow up. 
With regard to this character the position of L. stercorea is intermediate 
between that of the Pyronemaceae and such forms as Humaria gramdata. 
As in other members of the Pezizineae, a secondary mycelium grows 
downwards from the ascocarp and absorbs nourishment from the sub- 
stratum. 
General Conclusions. 
It seems clear that Lachnea stercorea adds another to the list of 
sexually reduced Ascomycetes. Further, it cannot be regarded as par- 
thenogenetic in the fullest sense, since the male gamete is replaced, 
as in Htimaria gramdata (Blackman and Fraser (4)), and in certain 
of the Uredineae (Christman (5), Blackman and Fraser (3)), by a female 
nucleus. 
Thus, with regard to its sexuality, Lachnea stercorea , in which the 
antheridium and trichogyne are present, though not functional, stands in 
a position intermediate between Pyronema confluens (Harper (17)) on the 
one hand and Humaria granulata on the other ; and it differs very little 
from such ‘ parthenogenetic * specimens of Pyronema as were obtained in 
artificial culture by Van Tieghem (21) and by Dangeard (7). It is, indeed, 
as has been elsewhere suggested (Blackman and Fraser (4)), not improbable 
that further investigation may show that, in such cases also, the functionless 
male nuclei are replaced by female. 
In Humaria gramdata reduction has progressed a stage further ; of 
the trichogyne, if such existed, there is no longer evidence, and the 
antheridium is also lost. In other particulars the structure and develop- 
ment of the archicarp, and indeed of the whole fruit, closely resemble 
those of L. stercorea. 
A trichogyne is formed in a considerable number of the Ascomycetes 
hitherto investigated. 
