Fungous Flora of the Soil 469 



Mycelium, in water cultures, fine. Hyphas uniform, 4-5/x broad, 

 branching lateral and sporulating in young cultures; sporangia terminal, 

 spherical, rarely oval, vacuolated, very variable in size, 30-58^1 in diameter, 

 with short tube of discharge, rarely equaling one fourth of the diameter 

 of the sporangium, placed in any position but usually opposite the stalk. 

 After discharge, growth of the supporting hyphse occurs through the 

 emptied sporangium or immediately below it laterally, new sporangia 

 being formed within the empty sporangium, or beyond it, in the first 

 case. Zoospores large, 3 to numerous; conidia unknown; oogonia within 

 and outside the substratum, terminal or often intercalary, 19-36JU in 

 diameter. Antheridia 1-3 or more from neighboring branches and less 

 frequently from the oogonial stalk. Oospores spherical, 16-27/z in 

 diameter. Germination by a hypha after a rest of several months. 



Hab. Found on dead insects in water and on vegetable debris in the 

 soil, Antibes, Calcutta, Dehra Dun, Butler. 



Pythium rostratum Butler, Mem. Dept. Agr. India No. 5, i : 84-86. pi. 5, 

 figs. 11-22. 1907. 



Mycelium in water cultures is large, often measuring 6 or even 8/z in 

 • diameter, tapering gradually at the ends, but never prolonged into fine 

 filaments, with branches irregularly racemose. Sporangia either terminal 

 or intercalary, being almost regularly spherical in the former case but often 

 oval in the latter, average 28^ in diameter, ranging from 23 to 34^. Zoo- 

 spores are normally liberated while the sporangium remains attached to its 

 bearing hypha. The tube of discharge is very large and broad, usually 

 about equal to the diameter of the sporangium, usually lateral in position. 

 Conidia are rarely as frequent as sporangia, and appear usually lateral. 

 They resemble sporangia in all respects except the mode of germination. 

 Oogonia intercalary or lateral, formed extramatrically, 2iyu in transveres 

 diameter and rather more longitudinally. Antheridium generally single 

 and usually arises from the hypha bearing the oogonium, sometimes 

 reduced to a hypogonal cell or a short lateral process arising from a cell 

 cut off immediately below the oogonium; the cell and process together 

 forming the antheridium. Oospores spherical, smooth, average 21/i, 

 extremes 12 to 26^1. 



Hab. Saprophitic in garden soil, Antibes, France, Butler. 



Pythium monospermum Pringsh., Jahrb. Wiss. Bot. i: 288. pi. 21, figs. 

 2-16. 1858. Butler, Mem. Dept. Agr. India No. 5, i: 71-73. pi. 2, 

 fig. 2. 1907. (See Butler for synonymy and further references.) 



Mycelium forming a cloud around the substratum. Hyph^ irregularly 

 branched, up to 7m in diameter, often with numerous bud-like outgrowths 

 laterally. Sporangia single or branched, zoospores from a few to 40 or 

 more. Oogonia within and outside the substratum, terminal or intercalary 



