348 
Faull. — The Cytology of 
what he takes to be conjugate divisions. What have been designated nuclear 
fusions in the oogonium he construes to be pseudo-fusions, for he finds a less 
intimate association between the pairing nuclei after they have entered the 
ascogenous hyphae. He is thoroughly satisfied in his own mind that all of 
the reported nuclear fusions in the gametangia (Harper (’96, ’05), Claussen 
(’05), Fraser (’08), &c.) have been misinterpretations of what were really 
pseudo-fusions — an explanation that lacks demonstration and hence open 
to some objections. 
A perusal of the literature of the last decade or more on this subject 
cannot but occasion amazement at the enormous amount of energy expended 
in the effort to determine whether or not nuclei fuse in the female game- 
tangium, and equally so at the meagre positive results that have been 
attained. Very probably some actual fusions have been observed, but the 
number is small, and if the theory of synkarions holds they may well be 
regarded as reversionary. On the other hand, the question of conjugate 
divisions has not been in the minds of most investigators, and so the subject 
has not been approached with anything like the same vigour from this angle. 
In spite of that, part of the ground in that direction has been cleared, and 
with promise that further effort will lead to a final solution. 
The first step in this connexion has long since been taken, for it has been 
proved again and again that the nuclei fusing in the ascus are not sister 
nuclei, but that they are daughters of the mother nuclei that undergo a 
simultaneous division. In other words, they afford an instance of conjugate 
division recurring with unfailing certainty at a definite stage in the life cycle, 
and which every one admits. Maire (’05) and Guilliermond (’05) have like- 
wise shown that both pairs of this division remain together in Galactinia and 
Acetabula , and that both are presumably capable of fusion. Some attempts 
to trace the ancestral lines of these nuclei farther back have been made, but 
as yet, with the exception of Claussen’s studies on Pyronema , any certain 
knowledge is fragmentary. Massee (’05) has pointed out that binucleate 
cells are characteristic of thalli of various Ascomycetes. McCubbin (TO) in 
a much more definite manner has shown that in Helvetia elastica there may 
be several conjugate divisions prior to fusion. Brown (TO, ’ll) reports the 
same features in Leotia and Lachnea. My own observations indicate that 
not only is this true of Helvetia , but it is demonstrable for a number of forms 
belonging to the Exoascaceae, Helvellineae, Pezizineae, Plectascineae, and 
Pyrenomycetineae, including the Hypocreales, Sphaeriales, and Laboulbeni- 
ales. The repeated proliferation of hooks and the fusion of terminal and 
antepenultimate cells as observed by McCubbin, and almost simultaneously 
by Brown, is not an abnormality, as Carruthers (’ll) would have it, but is 
an exceedingly common phenomenon in the Helvellineae and Pezizineae. 
Nor are conjugate nuclei restricted to the penultimate cells. Often, especially 
in the Plectascineae and Pyrenomycetineae, but also in some of the Disco- 
