FusARiA OF Potatoes 161 



On hard lima-bean agar, culture fourteen days old; conidiafrom a sheet 

 of small sporodochial masses spread over the substratum: 

 Conidia: 3-septate, 3 per cent, 41 x 3.2 n (only three measured) 



4-septate, 1 per cent 



5-septate, 96 per cent, 60 x 3.8 (52-70 x 3.5-5);u 



On wheat grain culture fourteen days old; conidia from small, semi-dry 

 sporodochia: 

 Conidia: 1-septate, rare 



3-septate, 14 per cent 



4-septate, 26 per cent 



5-septate, 60 per cent, 56 x 3.7 (49-64 x 3.3-4.1)^ 



Average of the above measurements : 

 Conidia: 0-septate, about 3 per cent 



1-septate, about 4 per cent, 17 x 3.1;u 

 2-septate, about 1 per cent 

 3-septate, about 20 per cent, 41 x 3.7 fi 

 4-septate, about 14 per cent 

 5-septate, about 58 per cent, 54 x 4.05^t 

 6-septate, very rare, 58 x 4.2^ 



VI. Section ArthrospORIELLA n. sec. 



Microconidia short and broad, spindle-shaped, 0- to 3-septate*^; sporo- 

 dochial macroconidia when present sickle-shaped, mostly 5-septate, of 

 Roseum type; pseudopionnotal microconidia mostly 5- and 5- to 7-, 

 often to 9- and more, septate, from slightly curved to straight and angui- 

 form; true chlamydospores absent; aerial mycelium from white to pale 

 buff and different hues of red and pink; color of substratum from clay to 

 different hues of red. 



The section is a connecting link between sections Roseum and Sporotri- 

 chiella (through F. arthrosporioides) . 



19. Fusarium diversisporum n. sp. (Fig. 16; PL vii, fig. 12) 

 Conidia varying from arthrosporial (short, spindle-shaped, and having 

 an average measurement when 3-septate and on aerial mycelium of 28 x 



'" These conidia, though often septate, represent an abbreviated type and thus can be termed micro- 

 conidia. These microconidia are often referred to as arthrosporial because of their resemblance to the 

 conidia of the genus Arthrosporium. 



