SAPROLEGNIA 4I 



Distinguished by conspicuous and mostly numerous pits, I^y the 

 occurrence in most cultures of cylindrical oogonia, by the frequently curved 

 stalks and necks of the oogonia, and by the scarcity of anthcridia, which 

 are mostly androgynous and borne on short, simple or little branched 

 stalks. 



Common in springs and branches, as Arboretum spring and brook. 

 Battle's branch, etc., appearing in 12.5% of all Chapel Hill collections 

 between February 15, 1912, and December 12, 1913 (see table); also 

 many times since. 



Distribution: Chapel Hill, N. C, Kentucky, Missouri, Massachu- 

 setts, Wisconsin, Michigan. 



For other illustrations see Pringsheim ('73), pi. 18, figs. 5 and 11; 

 W. G. Smith, ('78), 2 unnumbered plates; Minden ('12), figs, ib-c on 

 p. 520; Maurizio ('96), pi. i, figs. 28-36; Humphrey ('92), pi. 16, figs. 

 43-45; Lechmere ('iia), figs. 2-4; Klebs ('99), figs. 1-2 (or S. mixta); 

 Rothert ('88), pi. 10, figs. 1-13; Istvanffi ('95), pi. 35, figs. 14-18; Dangeard 

 ('90), pi. 5, figs. ^27. 



Minden ('12, p. 521) has described two forms of S.Jerax as follows: 



Form I. "Sporangia more inflated or spindleform than cylindrical, 

 often irregular in sections and with tapering tips; oogonia terminal, often 

 on long, bent stalks, typically spherical, if indeed at times with a cylin- 

 drical neck, very rarely cylindrical; antheridia very rare, but no more 

 so than in the tj-pical form. 



Form 2. " Like the typical except that the oogonia are borne mostly 

 on the ends of very short side branches in regular racemose arrange- 

 ment, which according to Fischer should not be the case in the typical 

 form. Many of the large oogonia, which contain numerous eggs, are 

 cylindrical in empty sporangia." 



It is obvious that this Form 2 is very like our Chapel Hill plant, 

 and it is also probably not different from Fischer's form in spite of sup- 

 posed discrepancies. Humphrey's slides show a plant similar to ours. 

 It is also to be noted that neither Humphrey nor we find the large number 

 of eggs, up to 40-50, in an oogonium which are recorded by deBary and 

 other European writers who seem to have copied from him (Fischer, 

 Minden). Pringsheim's figures 5, pi. 17; and 3, pi. 18, in his Jahrb. f. 

 wiss. Bot. 9, 1873, look suspiciously like our ^S. ferax, though labelled 

 by him Achlya polyandra. 



Saprolegnia esocina Maurizio is so near this species as perhaps to 

 fall well within its range of variation. It is described as differing from 

 the typical S. Thiireli in the size of the eggs, which are 21.5-25^1 in diam- 



