220 C. D. Sherbakoff 



On same medium as above, culture twelve days old; conidia from 

 pseudopionnotes : 

 Conidia: 0-septate, 12 per cent 



1-septate, 3 per cent 



2-septate, 2 per cent 



3-septate, 83 per cent, 31 x 4.3 (22-41 x 4-4.7)m 



4-septate, exceptional, 41 x 4.4/x (only one measured) 



On hard oat agar, culture twenty-four days old; conidia from a sporo- 

 dochium : 



3-septate, 100 per cent, 31.5 x 4.4 (23-35 x 3.8-4.7) /x 



Average of the above measurements: 

 Conidia: 0-septate, 30.5 per cent, 9.2x2.Sfx 

 1-septate, 5 per cent, 16.5 x 3.5/i 

 2-septate, 3.5 per cent, 22 x 4ju 

 3-septate, 61 per cent, 29.8 x 4.3 ju 

 4-septate, very rare, 41 x 4.4/^ * 



40. Fusarium oxysporum Schlecht.^^ (Figs. 1ni and 35a; PI. v, fig. 6) 

 Schlechtendal, Fl. BeroL, 2:139. 1824. Smith, E. F., and Swingle, 

 D. B., U. S. Plant Indus. Bur., Bui. 55. 1904. Wollenweber, H. W., 

 Phytopath. 3:28, fig. If. 1913. Wollenweber, H. W., Journ. Agr. Re- 

 search 2:268. 1914. 



Microconidia gradually pointed toward apex, nearly cylindrical in middle 

 half of their length, typically not broader toward apex, usually somewhat 

 distinctly pedicellate, 3-septate dominant, 30.4x4.2 (27.5-34 x 4-4.4) /i,^^ 

 in sporodochia and pseudopionnotes; 4-septate macroconidia frequently, 

 and 5-septate ones rarely, present; in mass usually of pinkish buff color; 

 aerial mycelium typically well developed, of medium height (from 3 to 5 

 millimeters) and density, from white to (in spots on boiled rice) congopink; 



*^ Original description of F. oxysporum Schlecht. (see von Schlechtendal, Flora Berolinensis_ 2 : 139) — 

 " t stroma convexum erumpens varium roseum superficie inaequali rugulosa, sporidiis parvis curvatia 

 utrinque acutissimis " — is insufficient for identification of the species, and, short as it is, it sooner suggests 

 some other species and not that of Smith and Swingle. For a detailed discussion of the matter see Appel 

 and Wollenweber (1910: 144-146). 



Wollenweber (1913 a : 28) gives his own description of F. oxysporum Schlecht., which, as he states (page 42 

 of reference cited), " includes some additions to the descriptions given by Smith and Swingle. "_ 



For the reason that, at least among pathologists and mycologists of the United States, this organism 

 is fairly well known under this name, and after Wollenwcber's description of it the meaning became 

 definite and recognizable, the name F. oxysporum is retained here and is used for the organism described 

 by Wollenweber without consideration of Schlechtendal's original description; that is, F. oxysporum, here 

 is as emended by Wollenweber. 



<9 Wollenweber (1913 a: 28) gives the size variation aa 25-45 x 3.25-4.5jtt. Whether this is average 

 or individual size variation is not stated. 



