1 70 Campbell.— Oil the Development of 
large number of spores that, finally, it was possible to get all 
of the stages. There is a good deal of difficulty in satis- 
factorily sectioning the youngest stages, too ; but a sufficient 
number of successful preparations were finally secured to 
make out clearly the earliest divisions in the prothallium, 
which Berggren, who alone has studied the female pro- 
thallium, failed to get, Berggren’s account of the prothallium 
is extremely imperfect, and is confined entirely to the later 
stages, and it was largely to determine the early stages that 
the work was first undertaken. 
The ripe macrospore does not become entirely free from 
the sporangium, the upper part of which remains covered 
by the cap-shaped upper part of the indusium. The more 
delicate lower part of the indusium, and the sporangium-wall, 
rots away and leaves the epispore exposed. From this the 
filamentous appendages stand out, very much as the glochidia 
do from the massulae ; and when the latter come in contact 
with the macrospore, the anchor-like ends of the glochidia 
become entangled in the filaments, and the massulae remain 
thus firmly attached to the macrospore. Of course this 
brings the germinating microspores close to the macrospore 
and facilitates fertilization. 
The most prompt germination of the macrospores was 
found in material gathered in early autumn, which is 
probably the ordinary time for germination. Spores col- 
lected late in November germinated, but less promptly. In 
all cases there is a good deal of variation, so that it is im- 
possible to state positively just how long is required. In 
a few cases, within eleven days from the time that the spores 
were freed from the plants and placed in fresh water, the 
young plants had already broken through the prothallium, 
and usually within two weeks this was the case. Probably 
the first divisions of the prothallium may occur within two or 
three days, and the whole development be completed within 
a week, but this is only an approximation, as there is no 
means of telling the stage of development without killing the 
prothallium. 
