ZOOSPORES IN SPIROGYRA CONDENSATA. 129 
cilia are seen to form a circular tuft at one end of the zoo- 
spores. While swarming, the zoospores appeared to be sur- 
rounded by a fringe of cilia. I was unable to determine the 
number of cilia. Their length was about equal to the diam- 
eter of the zoospore, which varied from 10 to 15 microns. 
They soon disappeared after the zoospore came to rest. Even 
while in motion, it could be seen that the zoospore was com- 
posed of two parts—a dense chlorophyll-green one sur- 
rounded by a hyaline mass. After coming to rest, this hyaline 
portion appeared to form a thick cell wall, the diameter of 
the central green portion being not more than half the whole 
diameter of the spore. 
I found no zoospores after March 29th. The parent fila- 
ments were then rapidly losing their healthy appearance, the 
contents becoming structureless and turning a yellowish 
color. By April 4th the cells had separated and had sunk, 
a brownish mass, to the bottom of the vessel. A few filaments 
kept in a life-slide did not disintegrate so rapidly, but were 
found to be infested by the hyphe of a fungus. 
Such an unusual phenomenon as the formation of zoospores 
in a member of the class conjugate led to a search for records 
of similar instances, and four meager notes were brought to 
light. 
Bennett & Murray in their Cryptogamic Botany, p. 264, 
state: “The reproductive organs of other alge or fungi, 
which are sometimes parasitic upon or endophytic in species 
of Spirogyra, have been mistaken for zoospores.” 
These of which I write, however, were certainly not the 
Spores of a parasite. Both Mr. Loy and I found them form- 
ing from the contents of the spirogyra cell, and there were no 
traces of a parasite in the cells in which the zoospores were 
formed, though, as stated above, fungal filaments subse- 
quently appeared in cells where no zoospores were formed. 
These fungal filaments were like the hyph of pythium, and 
had not begun to fruit. “2 
In Annals of Natural History, Vol. XIX. (1857), p. 260, 1s 
an article by H. J. Carter describing bodies somewhat similar 
