SAPROLEGNIA 3I 



etc., also in creek three miles north of Durham, N. C. Cultures from a 

 single spore produce typical growth with oogonia and antheridia. 



It is strange that this has not been described before, but there seems 

 no doubt that it is new. The thin oogonial wall with few rather obscure 

 pits, together with the preponderance of diclinous antheridia, would 

 indicate a relationship to the Diclimi group. It seems nearest S. ani- 

 sospora, which see for resemblances and differences. From S. diclina 

 it is distinguished by abundant oogonia, with few^er eggs (on average) 

 and pitted walls, at least a few of which have androgynous antheridia 

 at some stage of the culture; by the larger and more distinct antheridial 

 branches which last longer; by the more definite and thicker antheridia, 

 which are not so intricately wound over the oogonia (though sometimes 

 so numerous as to cover it) ; by much fewer gemmae, and by the appear- 

 ance of a part of the oogonia on lateral branches. 



It does not seem possible to refer this to S. seniidioica Petersen, as 

 the antheridia in that species, so far as can be made out from the descrip- 

 tion, are essentially androgynous, arising from beneath oogonia and 

 passing to the oogonia above as well as to others near. Moreover 

 the eggs of Petersen's plant are too numerous (6-15) and small (22^). 

 We agree with Minden in referring that species to 5. monoica (which see). 



In regard to the origin of its antheridial branches the species is 

 peculiar and apparently whimsical. As said above, the majority are 

 always diclinous (in the media studied) and in most vigorous cultures 

 on insects the proportion of oogonia with diclinous antheridia only is 

 very high, usually o\er 95% and often 99%. However, as such cultures 

 get older the per cent of such oogonia may drop to around 80% and 

 on a bit of boiled corn grain the oogonia with androgynous antheridia 

 may reach 25% (oogonia with androgynous antheridia nearly always 

 have diclinous ones also), and on whole egg agar in distilled water nearly 

 50%. Most androgynous antheridia are found away from the periphery 

 of the culture where racemosely borne oogonia are rather plentiful, but 

 on a corn grain even the terminal oogonia on main hyphae may often 

 have androgynous antheridia arising beneath (with diclinous ones also, 

 as a rule). The diclinous antheridia very often arise from hyphae which 

 also bear oogonia, as shown in the figures. 



There is a decided preponderance of apical oogonia. Where spor- 

 angia are not formed abundantly nearly all the oogonia are apical. 

 In the contrary case many are borne also on short lateral branches. 



The first four cultures below were made from a single spore cul- 

 ture of No. 9 of November 25, 1912: 



On bit of egg yolk in equal parts maltose 5% and peptone .01%. Extensive growth and 

 very abundant gemmae. \o sporangia or sexual reproduction. 



