144 THE SAPROLEGNIACEAE 



liferates to another one and empties itself into it [as is common in A. 

 proliferoides]. Eggs i to 12, mostly 4 to 8, diameter 24-31.551., eccentric; 

 germination not observed. Anthe.idia diclinous always, wrapping about 

 the oogonia. They generally proceed from more slender branches that 

 run among the oogonial branches. Fertilizing tubes were occasionally 

 observed entering the oogonia. 



Minden thinks this species should be united with A. prolifera if 

 the absence of a swimming stage should prove not constant. The eggs, 

 however, as described are too large for that species, and approach those 

 of A. flagellata. 



Achlya oligacantha deBary. Bot. Zeit. 46: 647, pi. 10, fig. i. 1888. 



This species has been reported only by deBary, and the following 

 is translated from the original: 



"Main threads slender and delicate. Oogonia on short or long 

 branches of hyphae which bear sporangia or in part terminal on slender 

 main threads and their racemose branches, spherical in shape, without 

 an internal upgrowth from the insertion wall of the somewhat enlarged 

 end of the stalk, surface always with relatively large, smooth, papillae, 

 which are separated from each other and which vary greatly in number 

 (i to about 16, very seldom none); also variable in size and form (short 

 points to large, blunt projections); wall of oogonia relatively thin, color- 

 less, without pits, except that the projections are mostly thinner than 

 the wall between them. Eggs mostly 4-8 in an oogonium (seldom up 

 to 12 or more), round, centric, relatively small. Antheridia always 

 present, mostly .several on each oogonium, relatively small, irregularly 

 spherical to cylindrical with the side against the oogonium; borne one 

 or two in a row, on the ends of partly androgynous, partly diclinous 

 antheridial branches. 



"Brought by Zacharias from a puddle at Kork (Baden) with S. 

 Thureti in June, 1881, and cultivated pure until 1883." 



The species seems certainly in the Apiculata group, but the structure 

 of its eggs is not quite cleared up by the word "centric." 



Achlya recurva Cornu. Ann. Sci. Nat. Bot., ser. 5, 15: 22. 1872. 



Since its first publication by Cornu this species has been reported 

 only by Hartog, who mentions it without description ('88, p. 212), and by 

 Minden, who refers to it a plant found by him and described as follows 

 ('12, p. 543): 



"Growth extending about i cm. from the substratum, with strong 

 main threads about 90;j. thick at base. Sporangia long, cylindric or 

 slightly spindleform; secondary ones few. Oogonia numerous, borne 

 terminally on certain little-branched, often slender main threads or on 

 more or less elongated, at times very long and branched side branches 

 which are always very slender and bent like a bow, and which spring 



