FusARiA OF Potatoes 227 



Hab. In discolored fibrovascular bundles of stem and tubers of Solanum 

 tuberosum, United States. 



This fungus and F. oxysporum var. longius are the organisms that 

 were found very commonly present in discolored fibrovascular bundles 

 of potato tubers and wilted plants. These organisms are also, as it seems, 

 most commonly recognized by various pathologists as F. oxysporum 

 Schlecht., as described by Smith and Swingle (1904); at least cultures 

 of organisms undoubtedly belonging here were received under the name 

 F. oxysporum from Mr. Wight in California, Dr. Taubenhaus in Delaware, 

 and Dr. Clinton in Connecticut. The chief difference between these 

 varieties of F. oxysporum of Smith and Swingle lies in the absence of sclerotia. 



Measurements of spores on different media are as follows: 



On slightly acidified hard potato agar, culture fifteen days old; conidia 



from thin pseudopionnotes : 



Conidia: 0-septate, 74 per cent, 8x2.7 (5-15 x 2-4.3) /x 

 1-septate, 9 per cent, 21 x 3 (12-27 x 2.3-4.8) /z 

 2-septate, 4 per cent, 26 x 3 (20-37 x 2.2-4.1)^ 

 3-septate, 13 per cent, 35 x 4.2 (22-57 x 3.5-4.7) m 

 4-septate, rare, 45 x 4.2/i 



On red raspberry cane plug, culture forty-seven days old; conidia from 

 aerial mycelium: 

 Conidia: 0-septate, 98 per cent, 6.5 x 2.7 (4.5-21 x 2.3-4.3) /x 



1-septate, 2 per cent, 18x3.2 (12-24 x 2.8-4. 1)^ 



2-septate, rare, 22 x 3.4 (17-24 x 3-4.1)/x 



3-septate, rare, 29 x 3.6 (19-36 x 3-4)^t 



On hard lima-bean agar with 2 per cent glucose, culture fifteen days old; 

 conidia from aerial mycelium: 

 Conidia: 0-septate, 97 per cent, 7.1 x 2.6 (5.2-16 x 1.8-4.3)^ 



1-septate, 2 per cent, 16x3.1 (10-18 x 2.3-3.8) /x 



2-septate, 0.5 per cent 



3-septate, 0.5 per cent, 28x3.5 (23-36 x 2.4-4) /x 



On corn meal agar, culture one hundred and seventy-three days old: 

 Chlamydospores : 0-septate, in conidia, 7.2 x 7 (5.8-9 x 5-8) yu 



0-septate, in mycelium, 9.6 x 8.3 (7-16 x 7-11. 5)ai 

 1-septate, in mycelium, 14.5x9.2 (13-18 x 7-ll)/x 



