1 70 THE SAPROLEGNIACEAE 



Apodachlya brachynema (Hildb.) Prings. (1883). See below. 



Apodachlya brachynema var. major Tiesenhausen (iqi2, p. 296, fig. 20). 



Apodachlya completa Humphrey (1893). The position of this plant is quite uncertain 



until further observations can be made. 

 Rhipidium interruptum Cornu (1871). 



Rhipidium continuum Cornu (1871). See also Petersen ('10, fig. 4a and e). 

 Rhipidium americanum Thaxter (1896). 

 Araiospora pulchra Thaxter (1896). 

 Araiospora spinosa (Cornu) Thaxter (1896). 

 Sapromyces* Reinschii (Schroeter) Fritsch (1893). See below. 

 Sapromyces androgynus Thaxter (1896). 

 Sapromyces elongatus (Cornu) Thaxter (1896). 



LEPTOMITUS Agardh, 1824, p. 47. 



Hyphae delicate, sparingly branched apically and soon appearing 

 dichotomous, constricted at intervals into distinct segments with a con- 

 spicuous cellulin plug separating them (thus differing essentially from 

 the Saprolegniaceae). Sporangia apical and then in rows in basipetal 

 succession. Spores in a single row (or nearly so), escaping as in Sapro- 

 legnia and of the same habit and structure (diplanetic), biciliate. Oo- 

 gonia and antheridia never observed. There is but one species now rec- 

 ognized as good, though many have been described. 



Leptomitus lacteus (Roth) Agardh. Systema Algarum, p. 47. 1824. 

 Apodya lactea Cornu. Ann. Sci. Nat. Bot. 15: 5. 1872. 



Plate 58 



Characters of the genus. The species may be found at almost any time 

 by taking slime from sewers or streams contaminated with sewage. In such 

 places it is often so abundant as to whiten all surfaces and objects in the 

 Water, as we have often seen in Chapel Hill and in Baltimore, Maryland. 

 Huxley (Quart. Jour. Mic. Sci. 22 : 331. 1882), quoting from Geoppert, says 

 that "refuse from a factory for making alcohol from turnips near Schweid- 

 nitz in Silesia, poured into the river Westritz, caused such a prodigious 

 growth of Leptomitus that the fungus covered some 10,000 sq. ft. of the 

 bottom with a thick white layer, compared {sic) to a sheep 's fleece, choked 

 up the pipes, and rendered the water of the town undrinkable. " See 

 also Bot. Zeit. 2: 163. 1853. 



Observations by Radais ('98, p. 147) on the behavior of the cellulin 

 granules are of sufficient interest to translate. He says: 



* Syn. Naegelia Reinsch (1878): Naegeliella Schroeter (1893). See Fritsch (1893, 

 p. 420). Tiesenhausen ('12) also reports this (p. 298, figs. 21, 22). 



