128 CD. Sherbakoff 



The measurements of the conidia in detail are as follows : 



On hard potato agar, slightly acidified, culture eighteen days old: 

 Conidia: 0-septate, 3 per cent 



1-septate, 97 per cent, 12.5 x 3.4 (10-18 x 2.9-4.1)^ 



On hard lima-bean agar with 2 per cent glucose, culture forty-three days 

 old: 

 Conidia: 0-septate, 12 per cent, 10 x 3.8/i 



1-septate, 88 per cent, 12 x 3.3 (10-18 x 3-3.5) /x 



On hard lima-bean agar, culture twenty-one days old : 

 Conidia: 0-septate, 27 per cent, 11.5 x 3.2 (9-14 x 2.9-3.5) ^ 

 1-septate, 73 per cent, 12.5 x 3.3 (10-17 x 2.9-3.9)iU 



Average of the above measurements: 

 Conidia: 0-septate, 14 per cent, 10.8 x 3.5/i 

 1-septate, 86 per cent, 12.8 x 3.3/i 



The organism studied is so much the same as F. dimerum originally de- 

 scribed by Penzig, that it is considered identical. A similar organism is 

 also reported as occurring on potato in Germany (Appel and Wollen- 

 weber, 1910:37). The only peculiarity of the organism which either was 

 not observed or was not present at all in the original F. dimerum is that the 

 septum in the conidia of the organism studied is often and conspicuously 

 acentric. 



II. Section Ventricosum Wr., Phytopath. 3:32 



Conidia only slightly dorsi ventral, somewhat wedge-shaped, broader 

 toward base, apex somewhat rounded, apedicellate, typically 3-septate; 

 no sporodochia; chlamydospores variable/^ always present. 



3. Fusarium ventricosum Ap. et Wr. 



WoUenweber, H. W., Phytopath. 3:32, fig. 1, a and v. 1913. 



Wollenweber describes this species as follows: "Conidia never formed 

 in sporodochia, brownish- white to cream-colored, 3-septate, 29-37 x 5.75- 

 7.5/x; conidiophores bostryx-like or irregularly branched, chlamydospores 



like those of the section Elegans. Wound parasite, found in 



Europe. Inhabits also Beta vulgaris." 



The organism was neither isolated nor studied by the writer. 



^^According to Wollenweber the chlamydospores are of Elegans type, that is, terminal and intercalary, 

 0- to 1- or more septate. In order to include F. cuneiforme it was necessary to alter the characterization 

 of the chlamydospores in this section. 



