confluens and the Morphology of the Ascocarp. 353 
vacuoles however does not constitute a very noticeable change 
as seen in the living cell, especially since in its earlier develop¬ 
ment the antheridium is decidedly vacuolar. It is interesting 
to see that the actual process and nature of fertilization 
in Pyronema could not have been discovered by the earlier 
observers, to whom the nuclei were invisible since it is 
practically the nuclei alone which pass over from the male 
to the female cell. 
The number of male nuclei which enter the oogonium does 
not appear to be exactly the same as the number of egg 
nuclei to be fertilized. I have counted them in several cases 
and found upwards of two hundred in each sexual cell. It 
is difficult to see, since oogonium and antheridium are each 
developed from a multinucleated cell to start with, and there 
is no evidence subsequently of a parallel series of nuclear 
divisions in each, how exactly the same number could be 
provided in each case. As a rule when fertilization is accom¬ 
plished by free motile male cells the latter largely outnumber 
the eggs. There is here no necessity for such excess, and 
the numbers, as I have pointed out, appear approximately 
equal. It will be seen however later that there is good 
evidence of slight inequality in the number on one side or 
the other, and that these supernumerary nuclei die without 
further development. It should be mentioned in this con¬ 
nexion that there is quite commonly an excess of antheridia. 
I have frequently found two antheridia applied to the surface 
of one oogonium, but only in one case have I found them 
in connexion with it (Fig. 21). In this case the conjugating 
tube was forked, sending a branch to each antheridium as 
the figure shows. Kihlmann describes a branching anthe¬ 
ridium connected with two oogonia. The supernumerary 
antheridia are abundantly filled with nuclei and seem normal 
in every respect. They do not however develop further, and 
may be found very frequently at a late stage of development 
protruding from the base of the hypothecium with their con¬ 
tents quite unchanged, except for the aggregation of their 
nuclei at the apex of the cell. This is at a time when the 
B b 
