1058 AQUATIC PHYCOMYCETES 



the oogonium, the total length of filamentous parts between the septa 

 delimiting the sex organs occasionally not exceeding 40 \l. Oospore color- 

 less or more often distinctly yellowish; smooth, subspherical, meas- 

 uring 1 1 to 54 [i, mostly 37 to 47 u, (average 41 .4 [*.) in diameter; provided 

 with a wall 0.8 to 4.6 \i (average 3.6 £x) in thickness, and containing a 

 reserve globule measuring at early maturity 6.5 to 24.0 y. (average 17.6 y.) 

 in diameter" (Drechsler, be. cit.). 



Causing a destructive decay of the stem and roots of Althaea rosea, 

 Drechsler (he. cit.), United States; rice seeds and seedlings, Ito and 

 Nagai (1931), Japan; saprophytic on apple (coll. Hall), Blackwell, 

 Waterhouse, and Thompson (1941), Great Britain. 



Waterhouse (comra.) believes Ito and Nagai's Pythiomorpha miya- 

 beana belongs here and, more specifically, that it is akin to the form 

 described by Tompkins et a/, in J. Agr. Res., 53 : 685. 1936. 



"Pythiomorpha Sp. Ill" of Lund (1934: 50, fig. 24 d-e), on twigs of 

 A Inns, Denmark, may perhaps be referable to this species. 



Phytophthora fischeriana (Hohnk), comb. nov. 



Pythiomorpha fischeriana Hohnk, Bot. Centralbl., 55 (Abt. A): 92, fig. 2. 

 1936. 



Mycelium intra- and extramatrical, the intramatrical hyphae stout, 

 constricted, and irregular, the extramatrical slender, 2-3 [x in diameter, 

 regular; zoosporangium ovate, 28-46 \i in diameter, renewed by cymose 

 branching of the sporangiophore; zoospores formed within the spo- 

 rangium, discharged as individuals at the rupturing of its tip, at first 

 irregular in shape but quickly becoming reniform, 10 \i in diameter, 

 with two lateral flagella; gemmae intercalary, ovoid, with thickened 

 walls, rarely terminal and spherical; oogonium apogamous, at maturity 

 bearing loosely within it a single egg with a thickened wall. 



On Alnus twigs in water, Hohnk {be. cit.', 1939: 351, fig. 6), Germany 

 (and the United States?). 



Waterhouse (comm.) believes this fungus is probably allied to Phy- 

 tophthora syringae (Kleb.) Kleb. She (1958) believes the species should 

 be left as incertae cedis and that the binomial be dismissed. 



