FusARiA OF Potatoes 175 



On hard lima-bean agar, culture nine days old: 

 Conidia: 0-septate, 14 per cent 

 1-septate, 28 per cent 

 2-septate, 5 per cent 

 3-septate, 32 per cent, 44 x 3.6 (29-63 x 3-4) ^u (exceptionally 



4.8^1 in diameter) 

 4-septate, 5 per cent 

 5-septate, 16 per cent, 65x3.9 (52-79 x 3.5-4.8) /i 



Average of the above measui'ements : 

 Conidia: 0-septate, about 10.4 per cent, 13.5x3.3/1 

 1-septate, about 20.4 per cent, 21 x d.bfj, 

 2-septate, about 9.2 per cent 

 3-septate, about 35.2 per cent, 41 x 3.9/x 

 4-septate, about 5.6 per cent 

 5-septate, about 18.4 per cent, 60.4 x 4.26// 

 6- and 7-septate, about 0.8 per cent, 82 x 4.9/i 

 8- and 9-septate, very rare, 85 x 5.2/i 



23. Fusarium arthrosporioides n. sp. (Figs. 1, l to p, and 20; PI. in, 

 figs. 3 and 4; PI. vii, fig. 11) 



Conidia of three types: (1) elliptical, apically attenuate, slightly 

 pedicellate, mostly 5-septate, 48 x 4.3 (45-55 x 4-4.7) /t; (2) arthrosporial, 

 0- to 3-(5-) septate, broad spindle-shaped, 3-septate measuring about 

 25x5.4 (19-33x4.7-6) At; (3) sporotrichial, mostly 0-septate, 4.5x3.8 

 (2.9-9 X 2.6-8) /t. Type 1 is found mostly in pseudopionnotes, type 2 on 

 aerial mycelium, and type 3 mainly in small, dense, bushlike clusters of 

 conidiophores, often resembling sporodochia; no true chlamydospores; 

 aerial mycelium from white to light tints of rose and salmon hues, uniform or 

 covered with knotted, more or less large, areas; substratmn from clay 

 color to buckthorn brown and bright red (Plate iii, fig. 4). The organism 

 occupies an intermediate position between sections Arthrosporiella and 

 Sporotrichiella. 



Hab. In discolored tissues of tuber of Solarium tuberosum, Ireland. 



The organism remained for a long time in pure culture, with well- 

 developed aerial mycelimn and with a bright red color (Plate in, fig. 4); 

 the dominant type of conidia was sickle-shaped, 5-septate. During the 

 last year — the second year of its cultivation — the development of aerial 

 mycelium has become poorer, the color of the substratum has changed to 



