confluens and the Morphology of the Ascocarp . 329 
of the ascocarp. Such a view would certainly represent the 
antithesis of that which has been recently current, according to 
which the Ascomycetes are entirely without sexuality. 
Dangeard professes to find some support for the view that 
the ascus is an oogonium in the method of reproduction of 
Eremascus and Dipodascus. He figures a parthenogenetically 
produced ascus of Eremascus as an illustration of the nature 
of the ascus in the Mildews and elsewhere. Whether there 
would be a fusion of nuclei in such a case is of course unknown. 
The facts as to the parthenogenetic development of some 
Crustacean-eggs in which the second polar nucleus fuses with 
the egg-nucleus might afford support for the view that a nuclear 
fusion is to be expected here, but, granting the relationship 
of Eremascus and Dipodascus to the other Ascomycetes, there 
can be no question that their sexual fructifications correspond 
to the entire ascogonia and asci of such forms as Sphaerotheca 
Erysiphe , Pyronema , Eurotium , &c., and not to a single ascus 
in one of these fruit-bodies. The gamete-cells of Eremascus 
and Dipodascus correspond to the initial sexual apparatus of 
the mildews and Pyronema, and not to the pair or pairs of 
nuclei in the ascus. This is the interpretation given by Eidam 
and Lagerheim themselves, and Dangeard brings no evidence 
against it. Indeed, in his whole paper, Dangeard seems to be 
seeking to save his original proposition, that the ascus is an 
oogonium, against the evidence of his own observations on 
Sphaerotheca . The whole argument seems like an elaborate 
attempt to escape from the unenviable position of having 
proposed a theory as to the sexuality of the Ascomycetes, 
which simply ignored a mass of fully described, easily veri¬ 
fiable facts in the development of so simple a form as 
Sphaerotheca. 
On one point as to the general structure of the ascocarp of 
Sphaerotheca , Dangeard disagrees with me and holds a 
position nearer to that of De Bary. He finds that the mature 
ascogonium consists of only three cells, the middle one of 
which forms the ascus, while I have found regularly five or 
six cells in the mature ascogonium, of which the penultimate 
