FIG. 206. Edogonium nodosum, a Conferva form : A, portion of a filament showing a 
vegetative cell with its nucleus (d), an oogonium (a) filled by an egg packed with 
food material, a second oogonium (c) containing a fertilized egg or oospore as 
shown by the heavy wall, and two antheridia (6), each containing two sperms; B, 
another filament showing antheridia (a) from w y hich two sperms (b) have escaped, 
a vegetative cell with its nucleus, and an oogonium which a sperm (c) has entered 
and is coming in contact with the egg whose nucleus (rf) may be seen; C, a zoo- 
spore which has been formed in a vegetative cell, showing the crown of cilia and 
the clear apex, as in the sperms; D, a zoospore producing a new filament, putting 
out a holdfast at base and elongating; E, a further stage of development; F, the 
four zoospores formed by the oospore when it germinates. CALDWELL, except 
C and F, which are after PRINGSHEIM. 
