190 C. D. Sherbakoff 



On hard lima-bean agar, culture fourteen days old ; conidia from minute 



converging sporodochia close to substratum: 



Conidia: 3-septate, 3 per cent 

 4-septate, 1 per cent 



5-septate, 95 per cent, 49 x 4.2 (41-63 x 3.5-5.3) /z 

 6-septate, 1 per cent, 54 x 4.7/i (only a few measured) 



Average of the above measurements: 

 Conidia: 0- to 2-septate, very rare 



3-septate, 13 per cent, 38 x 3.5/x 

 4-septate, 13.5 per cent 

 5-septate, 72.5 per cent, 49.2 x 4/x 

 6- and 7-septate, 1 per cent, 53.6 x 4.3^1 



The organism occupies an intermediate position between section Roseum 

 and section Ferruginosum; its type of conidia is that of section Roseum, 

 while because of its true chlamydospores of only arf intercalary kind it 

 belongs to the section Ferruginosum. 



An especially striking peculiarity of F. arcuosporum is the frequent 

 occurrence, especially in young cultures on various agars, of conidia with 

 more or less distinct branches and knobs (Fig. 23 o). 



28. Fusarium ferruginosum n. sp. (Figs. 1, h to j, and 24; PI. in, 

 figs. 9 and 10; PL vi, fig. 2) 



Conidia well developed, in from small to medium-sized (up to 2 milli- 

 meters in diameter) sporodochia or hi pseudopionnotes, very gradually 

 pointed toward apex, distinctly pedicellate, more or less strongly arcuate, 

 and broader in the middle or in the lower third of their length, typically 

 3- to 5-septate; 5-septate average 45.3x4.2 (28-53 x 4. 1-4.2) /i; conidia 

 from aerial mycelium — sometimes also from sporodochia produced on 

 very oldagar cultures — typically 3-septate, 30.8x3. 8/i, mostly apedicellate; 

 conidia from nearly white to pale pink buff and deep vinaceous in color; 

 intercalary chlamydospores in mycelium always present, often very 

 numerous, in long chains and large clusters; aerial mycelium always 

 well developed, high, often very dense, white at first changing to pink 

 and then ferruginous when mature, the last-named color being due to 

 production of great masses of chlamydospores; color of substratum, on 



