foie OED OGONIACEAE at 
-found in considerable mats on the surface of the water. There 
is no holdfast cell in Oedocladium. 
In many of the larger species of the genus Oedogonium, 
in particular, and rarely in Bulbochaete the protoplast of the 
cell may form ovoid, ellipsoid, or irregularly shaped aplano- 
spores. In the terrestrial species of Oedocladium resting cells 
or ‘‘akinetes’’ occur on the rhizoidal filaments. They are in 
reality few-celled side branches with swollen cells containing 
reserve foods. Similar reserves sometimes accumulate in the 
vegetative cells and can thus endure prolonged desiccation 
(Stahl 1891). Such cells upon subsequent growth (‘‘germi- 
nation’’) may produce new plants. 
There has been considerable speculation regarding the 
relationship between the macrandrous and nannandrous species 
of the Oedogoniacee. Hirn (1900) and West (1912a) are of 
the opinion that dwarf males of the nannandrous species (at 
least of Oedogonium) arose by the reduction and greater 
specialization of the zoospores normally producing the anther- 
idial filaments of the macrandrous forms. They would assume 
as a beginning that the monoecious filaments as well as the 
zoospores are hermaphroditic. Differentiation of zoospores, 
some producing antheridial filaments only and others producing 
oogonial filaments only, gave rise to the dioecious, macrandrous 
species. Small male filaments of such plants as Oe. fonticola 
or Oe. verrucosum perhaps represent intermediate steps in further 
reduction and specialization leading to the dwarf male, epi- 
phytic on or near the oogonium. Schaffner (1927) regards the 
androspores as having been derived phylogenetically from 
original sperms and as retaining sexuality to some degree; 7.e., 
they react toward the oogonium or suffultory cell sufficiently 
to lodge there, but not sufficiently to fuse with the egg. The 
dwarf male is thus formed parthenogenetically from an andro- 
spore. Pascher (1907) on the other hand states that the 
nannandrous species are not derived from the macrandrous 
species. 
The numerical composition of the three genera of Oedo- 
goniaceze based on the nature of the sexual reproduction in the 
species presents an interesting comparison. In the genus 
Bulbochaete 42 species, 2 varieties, and 1 form are dioecious, 
nannandrous; 6 species, 2 varieties, and 1 form are monoe- 
cious; no dioecious, macrandrous species are now known. 
