Il8 THE SAPROLEGNIACEAE 



It is also to be noted that while the gemmae in this species may 

 become somewhat loosened at the points so as to bend back a little, 

 they are far less inclined to this than in A. imperfecta, and we have never 

 seen them fall away as so often happens in that plant. Dictiosporangia 

 are not rarely observed and have been illustrated by us ('12, pi. 78). 



ID. Achlya imperfecta n. sp. 



Achlya deBaryaiia var. intermedia Minden. Krypt. Fl. Mark B. 5: 



545- 1912. 



Plates 38 and 39 



Growth dense or rather open, not very long, many stout hyphae 

 with more slender branches, tips hyaline, often dying and then a new 

 growing point produced below. Sporangia plentiful, subcylindrical, little 

 larger than the hyphae that bear them, not very long as a rule, often 

 irregular and twisted. Spores about io-ii.5sjl thick, dark, emerging as 

 usual but often falling to the bottom in an open group instead of form- 

 ing a sphere at the sporangium mouth. Gemmae formed by the seg- 

 mentation of the hyphae, therefore mostly subcylindrical and in rows, 

 but often ovate and frequently with knobs or projections at one or both 

 ends. Any part of the culture may be segmented into gemmae even 

 to parts of the antheridial branches. They often become loosened from 

 each other in part, rather rarely completely separating and falling singly 

 to the bottom. Oogonia usually abundant, spherical, 37-6o:j. thick, 

 most about 40-45ti., borne racemosely on short stalks about }4-i/4 times 

 as long as the diameter of the oogonia; wall without pits, or with several 

 to numerous small, inconspicuous ones; from the basal wall a protuber- 

 ance of varying length is present in many cases, and there are rarely 

 present one or two papillate protuberances fpl. 38, figs. 2 and 8). Eggs 

 eccentric, with a large oil drop, 2-8 in an oogonium, commonly 4-6, 

 diameter 17-23^1, most about 19.5-2010., often elliptic from pressure. 

 The great majority of the eggs go to pieces before maturity. Anther- 

 idial branches androgynous or declinous, variable in origin and length, 

 usually branched and irregular, arising from hyphae that also bear oogon- 

 ia and then applying themselves to nearby oogonia or most often by 

 extensive growth and branching to more distant oogonia either on the 

 same or other hyphae; or certain threads may give rise to antheridial 

 branches only which then seek out oogonia on other threads. 



Found many times in Chapel Hill in springs, ditches, branches and 

 creeks. Also found in material collected near Fayetteville, N. C, July 10, 

 1920, by Miss Holland. Pieters illustrates (unpublished notes) a species 

 that is certainly this or A . proliferoides, the antheridia sometimes androgy- 

 nous, prevailingly diclinous. As he shows no coiling antheridial branches 

 we refer his plant provisionally to this species. The plant he illustrates is 

 presumably the one he has studied in various media under the name A. 

 prolifera ('15b, p. 529) as his drawings are labelled A. pro! if era. The plant 



