322 



THE JOUENAL OF BOTANY 



the filaments were dissociating owing to the formation of 

 immense numbers of apparent zoogonidia. These were in all 

 stages of germination among the fragmenting filaments. The 

 average vegetative cell is very short (scarcely as long as broad), 

 but the cells from which the zoogonidia were being set free were 

 still shorter. All the young plants were much thinner than the 

 filaments on which the oogonia were developed and from which 

 the motile gonidia originated ; they were also very short. Hence, 



Fig. 1, A. — Three generations of CEdogonium rivulare, tvfo unicellular plants 

 and an escaping zoogonidium (z). (x310.) 'B-ll,GE.fonticola. B, female plant 

 with two oogonia containing oospores (os), and two androzoogonidangia {az) each 

 containing a single immature androzoogonidium ; C and D, young male plants 

 which were attached ; E-H, developing androzoogonidia which were unattached, 

 showing the much-branched holdfast, x 330. 



N. B. — Fig. 1 B represents one of the very few filaments observed with 

 oospores, as in most cases the oogonia were either only just developing or they 

 contained unfertilized oospheres. 



it seems probable that large numbers of small male filaments 

 were being rapidly developed during the formation of the oogonia 

 on the female filaments ; and should this prove to be the case, 

 then CE. fonticola is a dioecious macrandrous species with very 

 reduced male filaments, exhibiting a condition intermediate 

 between truly dioecious macrandrous species and those with 

 large nannandria. 



Further investigation was unfortunately prevented by the 



