86 THE SAPROLEGMACEAE 



calary or in chains of two or three, sometimes cylindrical inside old 

 sporangia; diameter 24-75'ii, most about soyi, wall clear at first, dis- 

 tinctly yellowish in age, about 2.8ix thick, with few (usually 2 or 3 visible) 

 very large and conspicuous pits. Eggs few, usually one, often two, 

 rarely three and very rarely four, i8.5-43(x in diameter, most about 

 32-35UL when two in one oogonium or 40-45[x when only one; centric. 

 Antheridia never developed. 



Found four times by Mr. J. N. Couch, April 25, 1918, and June 22, 

 191 8, in a drinking trough for horses about 2J2 miles east of Chapel 

 Hill; and April 30, 1918, and February 18, 1921, in the marshy 

 place opposite cemetery in Battle's Park. 



Dififers from I. tondoides in larger and fewer eggs, more scorpioid 

 arrangement of oogonia at times, and absence of antheridia. This 

 peculiar species has a decided resemblance to Pythiopsis Humphrey- 

 ana in its few large eggs, appearance of the oogonia, cymose branch- 

 ing, etc., but the latter, as well as P. cymosa, has monoplanetic spores. 

 There is a tendency, though not a strong one, for the oogonia when in 

 chains to become separated from each other; in this respect, as well as 

 in the yellowish walls, approaching 5. monilifera. There are formed not 

 rarely at the base of the oogonia ingrowing tubes through the 

 partition wall. These usually reach the egg and may indeed run along 

 the egg surface and approach the distal side of the oogonium. Such tubes 

 do not seem to be in any sense antheridia, as they not only do not discharge 

 but become thick-walled and often nodulated. In an ordinary culture 

 in distilled water spores were seen to emerge at 10:04 A. M., and swim slug- 

 gishly and aimlessly; some came to rest in less than a minute, all in about 30 

 minutes, at temperature of 86° F. A similar observation was made on 

 another collection about three years later. Spores swam from one-half 

 minute to thirty minutes, most coming to rest after twenty minutes. 

 It is remarkable that after repeated renewal of cultures in the laboratory 

 the color in the oogonial walls tends to disappear. This is true also of 

 Achlya color ata. 



IMaurizio described a new species, Saprolegnia bodanica, which is 

 apparently in the same group as 5. monilifera, and S. torulosa. S. bo- 

 danica has no antheridia and has a somewhat irregular habit of growth. 

 In these two ways it is similar to Isoachlya unispora. But the two 

 species are distinct in that the latter never has over 4 eggs in an oogo- 

 nium, and usually has only one, while none of Maurizio's figures show 

 an oogonium with one egg, and most of them have over four; the oogonia 

 in Isoachlya unispora have from one to several (usually 2 or 3) large 

 pits, while the oogonia of 5. bodanica have (in Maurizio's figures) 9-1 1 

 pits. 



