No. 464.] STUDIES ON PLANT CELL.— VII. 563 
were investigated and no developments from the carpogonia 
were found, but the cystocarp in all cases arose from a cell near 
the base of the group of procarps. These conditions together 
with the rarity of male plants on the American coasts (none 
have ever been reported) give strong evidence for apogamy in 
Ptilota. There are a number of genera of the Rhodophycez 
where similar conditions seem to obtain and which lead one to 
suspect that apogamy may not be very exceptional. However, 
the subject has been very little studied. 
As is well known, the Ascomycetes furnish numbers of illus- 
trations where ascogonia have not been found or appear in what 
seem to be reduced conditions and even when accompanied by 
so called antheridial filaments these latter have not been estab- 
lished as functional. De Bary recognized the possibility of 
apogamy in the development of the ascocarps of these forms 
and very little critical study has been given to them since his 
time. The trend of. investigations in this group has been 
towards the more interesting problems of the establishment of 
sexuality in a few well known forms (e. g., Gymnoascus, Sphe- 
rotheca, Pyronema, Monoascus, and among the lichens and 
Laboulbeniacez.) 
It is generally believed that no sexual organs are present in 
the higher Basidiomycetes (Autobasidiomycetes). But the 
recent studies of Blackman (:04a) in the Uredinales, taken in 
relation to the well known nuclear fusions in the basidium, pre- 
ceded by a mycelium containing paired (conjugate) nuclei, make 
it seem very probable that former sexual processes in the Basi- 
diomycetes have been replaced by a remarkable type of apog- 
amous development of a sporophyte generation. Blackman has 
traced the origin of the paired nuclei in the Uredinales (Phrag- 
midium) to a structure preceding the ecidium, a structure which 
seems to be the remains of a female sexual organ. We will 
take up this investigation presently. There is then much 
reason for believing that a sporophyte generation in the Basi- 
diomycetes arises apogamously in the creation of the paired 
- nuclei and terminates with their fusion within the teleutospore 
or basidium. 
The leptosporangiate ferns have furnished some of the best 
