134 THE SAPROLBGNIACE^ OF THE UNITED STATES, 



Aplanes DeBary ('88). 



This genus represents the extreme result of the reductional tendencies observed 

 in previous genera, in that both swarming stages are entirely suppressed. The zoo- 

 spores encyst within the sporangium and germinate there, producing germ-tubes 

 which penetrate the sporangial wall and thus make their way into the surrounding 

 water. 



Aplanes androgynus (Archer). 



Syn.: Saprolegnia androgyna Archer ('67). 111.: Archer, '67, PL VI, Fig. 1. 



Achlya Braunii Reinsch ('78). Reinsch, '78, V\. XIV, Figs. 1-6. 



Aplanes Braunii DeBary ('88). DeBary, '88, PI. IX, Fig. 2. 



The present YQvy striking species would seem not to be rare in Europe, having 

 apparently been met with by several investigators ; but it is not known to be Ameri- 

 can. It is recognized by its several spored, barrel-shaped or spiudle-shaped oogonia, 

 with pitted walls, often formed in series from a hypha, and by its numerous antheri- 

 dial branches arising just below the basal wall of each oogonium, even though it be 

 from the sides of the next oogonium in the series. 



Although it is not absolutely certain that the plants studied by Archer, Reinsch, 

 and DeBary all belonged to the same species, there seems to be little doubt of the 

 correctness of such a conclusion, in spite of the fact that Reinsch's account of the 

 sporangia does not agree with DeBary's, and that Archer does not mention the pits 

 of the oogonial wall. The overlooking of the latter would have been less remarkable 

 twenty-five years ago than to-day ; and Archer's failure to see the sporangia is 

 readily explained by DeBary's statement that they are very rarely developed. 

 Archer's arguments for placing his plant in the genus Saprolegnia are drawn wholly 

 from analogy, and not from observation of the sporangia. 



Reinsch's description of the sporangia suggests that he perhaps did not see those 

 of the plant whose sexual organs he studied, but mistook for them those of a Dictyu- 

 clius which may have grown intermingled with the other. At all events, the agree- 

 ment in the structure of the sexual organs has led DeBary to feel very sure of the 

 identity of his plant with Reinsch's, but he seems to have overlooked the equally 

 complete similarity of Archer's plant. It seems best, then, to consider all the names 

 above quoted as synonyms ; and, while retaining DeBary's generic name, the plant 

 must bear the specific designation given it by Archer, since that is the older. 



