78 THE SAPROLEGNIACEAE 



the principal stem of the plant or from any neighboring portion of the 

 general plant, but these are given off from the oogonium itself, which 

 is next immediately beneath the oogonium which is fertilized by them, 

 and so on down to the lowest or basal oogonium of a series, to which 

 last are gi\en off lateral male branchlets from the original filament or 

 stem immediately thereunder. The tube or cavity of each lateral male 

 branchlet becomes shut off by a septum formed a short distance above 

 its origin, the portion of the contents above the septum being de\eloped 

 into the male element — that portion of the contents below the septum 

 retaining its characters, and being returned back into the oogonium 

 whence it originated in time to become employed, with the remainder 

 of the contents, in the formation of the oospores. Oospores large, about 

 830 of an inch in diameter, mostly numerous, but very \'ariable in num- 

 ber, sometimes, though rarely, as few as even one. They occasionally 

 exhibit what appears to be a roundish eccentric \acuole. The whole 

 plant large and coarse as compared with other described forms in this 

 family." 



In an introductory discussion Archer states that he saw no zoospores 

 but is led to place the species in Saprolegnia because he once found a 

 group of three empty sporangia, one within the other, each with a terminal 

 opening. The one good figure shows four barrel-shaped oogonia in a row, 

 the apical one with a terminal papilla. Thickness of wall or pits not shown. 



Humphrey points out that Saprolegnia androgyna Archer is the 

 same in all probability as Achlya Braiinii Reinsch and as A planes Braimii 

 deBary. DeBary, with slight reservation, thought his plant the same 

 as Reinsch's, but overlooked the similarity of S. androgyna. Reinsch 

 states positively that sporangia occur which show cell nets after the 

 escape of the spores. He also says that in most cases after the emergence 

 of the spores the cell nets are not visible, indicating that they disappear 

 soon. His implication throughout is that the spores always escape as 

 in Dictyuchus, and one of his figures (fig. 5, pi. 14) clearly shows this 

 method. However, in fig. 2 he shows two sporangia attached to an 

 oogonium which are empty and show distinct openings for the discharge 

 of the spores. In fact Reinsch did not observe at all the "Aplanes 

 type" of spore germination, as deBary later described it (Bot. Zeit. 46: 

 651. 1888). When we remember that deBary speaks of the sporangia 

 as of great rarity, it seems to us that we are entirely unjustified in as- 

 serting that the spores of Aplanes have no swimming stage. All of 

 Reinsch's testimony, as well as Archer's, is the other way, and as Fischer 

 says ('92, p. 367) there can be no doubt that Reinsch 's plant and deBary's 

 are the same. In his description of the genus Fischer admits that net 

 sporangia (as in Dictyuchus) seem also to occur occasionally. 



Minden finds a plant (191 2, p. 573) that he thinks is Achlya Braiinii 

 of Reinsch {Aplanes of deBary) and he gives one figure of the oogonia 



