1896.] Aquatic Fungt. 49 
veloped; in other words the former are characteristic of the 
earlier, the latter of the later conditions of the plant. In or- 
igin these spores correspond in all respects to the sporangia; 
arising as buds from the surface of the swollen extremities of 
the axis from which they are soon separated by a septum. As 
they mature they usually assume a more or less oval form, be- 
come very thick walled and when ripe fall readily from their 
attachment, leaving a circular scar. The mature spore has two 
walls, an outer, thin and even, and an inner, thick and curiously 
Modified, so as to present the appearance represented in fig. 
12, when viewed in optical section. Whether the character- 
istic markings figured are really pits, as they appear to be, 
can hardly be definitely determined without an examination 
of an absolute section of the wall, and such a section has not 
been obtained. The surface view of these ‘‘pits” is repre- 
sented by the circular outlines shown in fig. 13. Several 
tinued for more than a month. In form they vary almost as 
Much as the sporangia; being in some cases quite spherical, 
with a small papilla of attachment as in figs. 8 and 9, in oth- 
~s Nearly oval with a broad base as in fig. 7, or long piri- 
‘es There is, however, a notable tendency in 
given plant to produce resting spores of a given form even 
fe fe 8 this form is ‘an unusual one. 
in naturally suggested the possibility of the existence 
rst but ¢ gatherozoids similar to those found in Monoblepha- 
Poa Sag is certainly only one kind of sporangium, and 
all cases €rozoids in reality existed, it would be, in almost 
from th tee impossible for them to perform their office 
form «oct that, by the time the resting spores begin to 
