13 



trary to Bertliold's observations, both kinds of sporangium 

 occur on the same plant. He further states that he 

 obtained young plants from the mega-zoospores alone. 



Perhaps the most interesting point in Went's paper is 

 his discovery of the fact that the sporangium may, instead 

 of developing zoospores, germinate itself directly into a 

 new filament, branching even whilst still attached to the 

 parent "palisade cell." Went terms these "abnormal 

 sporangia," and suggests the possibility of their being galls 

 due to the presence and stimulating action of Rotifera, just 

 as the Rotifer Notommata produces galls in Vaucheria. 

 He admits, however, that he saw no evidence for the 

 presence of any parasite. 



Turning now to our own observations, we find that the 

 sporangia are produced plentifully during the winter 

 months, and are in the form of much elongated ovate 

 bodies arising from the sides of the upper half of the 

 "palisade cells" (PL IH., figs. 15, 17, 18; PI. II., fig. 

 5). Usually one sporangium is borne on each "palisade 

 cell," but there may be a succession from the same cell, as 

 is evidenced by the existence of scars indicating the points 

 of attachment of older sporangia (PI. II., fig. 5, and PI. III., 

 fig. 18). In other cases two or even three sporangia may 

 occur together (PL II., fig. 5, and PL III., fig. 17). Each 

 sporangium as it ripens becomes separated from the parent 

 palisade process by an annular septum similar to those 

 found in the vegetative part of the thallus. The wall of 

 the sporangium is distinctly two layered, the outer layer 

 being thin and well defined, the inner somewhat thicker 

 and capable of swelling considerably. For the most part 

 the two layers are in close approximation, but at the base 

 and also at the apex they separate when the sporangium 

 becomes mature. In fig. 15, PL III., a ripe sporangium is 

 illustrated, where it will be seen that the inner wall is 



