Humaria rutilans , Fries. 
43 
as reaching maturity without the formation of sexual organs. The small 
size of the nuclei will in many cases, no doubt, render the actual observation 
of this process very difficult. 
Formation of the Ascus. 
De Bary (14, 16) first observed the presence of a single nucleus in 
the comparatively young ascus. He discovered that it underwent three 
successive divisions and that, about each of the eight resultant nuclei, a spore 
is normally organized. His observations were confirmed by Strasburger (39), 
by Schmitz and by Gjurasin (22), who also discovered in Peziza vesiculosa 
that the nuclear divisions are karyokinetic, and that well-marked asters 
are present. 
In 1894 Dangeard, investigating P. vesiculosa and some other forms, 
made the important observation that the ascus originates from the binucleate, 
penultimate cell of an ascogenous hypha, and that the two nuclei of this cell 
fuse to form the definitive nucleus of the ascus. The bending over of 
the ascogenous hypha, the simultaneous karyokinetic division of the two 
terminal nuclei in such a way that the nuclei enclosed in the ascus shall 
not be of the relationship of sisters, and the fusion in the ascus have since 
been confirmed in a number of other species. 
Recent research, however, has brought to light various modifications 
of this method. Maire (32), in 1903, discovered that, in Galactinia succosa , 
the two or three end cells of the ascogenous hypha are binucleate, the ascus 
being formed from the terminal cell ; here also the two nuclei of the ascus 
are not sisters. 
In Peziza Catinus , according to Guillermond (25), the bending over of the 
ascogenous hypha does not take place, otherwise development is typical. 
Faull (19), in 1905, described, in Geneahispidula and a number of other 
species, the outgrowth of the ascus from the curved terminal cell of the 
ascogenous hypha ; he regards this process as differing from the typical 
one only in the absence of a wall cutting off the recurved tip of the hypha. 
He makes no suggestion, however, as to the fate of the nucleus usually 
contained in the tip. He records the further interesting observation that 
in Verpa bohemica the ascus may grow out from the terminal cell of the 
hypha or it may arise from the second, third or fourth cell from the end, 
the growth of the hypha continuing beyond it. In one or two other forms 
the ascus may apparently spring from any cell whatever. Faull finds that 
the nuclei which fuse in the ascus, though not sisters, may be the daughters 
of sister nuclei. 
Harper (31), both in Erysiphe and in Phyllactinia ) found that the asci 
arise from binucleate cells of the ascogenous hyphae. There is no process 
of bending over, and no provision to prevent the inclusion of sister nuclei. 
In Humaria rutilans , as in Verpa bohemica , the ascogenous hypha may 
