1922] Water Mold Related to Blastocladia 181 



Found only once, October 20, 1921, on a knuckle bone of beef 

 partly covered with water, in Sparrow's pasture, Chapel Hill, N. C. 

 (F. A. Grant col.)- 



There is no doubt of the close relationship of this plant to Blasto- 

 cladia of which four species are now known, and which was made the 

 type of a new family, Blast ocladiaceae, by Minden (Crypt. Flora, 

 Mark Brand. 5:506. 1912). The four known species of 5Za!5^ocZadia 

 are as follows : 



Blastocladia Pringsheimii 'Reinach (Jahrb. f. Wiss. Bot. 11:291. 1876). Sporan- 

 gia much elongated, resting bodies with thick and pitted wall, not slipping 

 from a sheath at maturity; sterile, slender filaments often present among 

 the reproductive bodies. 

 Blastocladia rostrata Minden (1. c, p. 604). Much like B. Pringsheimii, but 



resting bodies slipping from sheath at maturity. 

 Blastocladia ramosa Thaxter (Bot. Gaz. 21:50. 1896). Sporangia shorter; 

 resting bodies with thin and scarcely pitted wall; sterile filaments absent. 

 Blastocladia prolifera Minden (1. c. p. 606). Much like B. ramosa, but 

 sporangia proliferating internally, as in Saprolegnia: the only species 

 with this habit. Eesting bodies slipping from a sheath at maturity. 



In the form of the sporangia and resting cells and in the absence of 

 sterile filaments among them our plant resembles most closely B. ram- 

 osa and B. prolifera. The remarkable resting bodies with their thick 

 brown, strongly pitted walls and peculiar habit of slipping at maturity 

 from the closely fitting sheath are so strikingly similar in structure 

 and habit to those of B. rostrata and B. prolifera and in structure to 

 those of B. Pringsheimii that one is immediately convinced of their 

 close relationship. The diagnosis of the family will have to be ex- 

 tended to include septate as well as non-septate forms. 



On an agar plate the plant does not do well, A few root-like 

 threads grow out, branched and with cross-walls in the older portions, 

 and in these older portions are found resting bodies or sporangia, 

 sometimes fifteen or twenty of the latter may be in a row. The re- 

 productive bodies are sometimes found in clusters or single on short 

 lateral stalks. 



On boiled corn grain the growth is good. The threads are about 

 the same size as on an ant but average longer, as much as 5 mm. The 

 protoplasm in threads is not as dense as when grown on ant. 



Threads at substratum as large as 102/^ in diameter. Sporangia 

 are produced better than on ants, and resting bodies are so abundant 

 that with the unaided eye they give a brick dust color to the entire 



