Apr.s, igis Relation of Soil Fungi to Potato Diseases 91 



ent on starchy media and steamed melilotus stems, from ox-blood red 

 to sepia-brown and black; sporodochia salmon-orange to ochraceous- 

 orange and buckthorn-brown (on string-bean agar). Chlamydospores, 

 terminal and intercalary, singly and in chains and groups. 



Habitat: Isolated once from Idaho soils, from group A. This organ- 

 ism failed to produce a decay when inoculated in potato tubers. 



The measurements of the conidia on various media are as follows : 



FROM AERIAL MYCELIUM ON STEAMED-POTATO PLUG, CULTURE 52 DAYS OLD 



I -septate rare. 



2-septate 9 per cent, 20 by 3.9 (17 to 26 by 3.6 to 4.8) ju. 

 3-septate 42 per cent, 30 by 5 (18 to 36 by 3.6 to 5.9) /i. 

 4-septate 40 per cent, 36 by 5.5 (24 to 43 by 4.2 to 6) n. 

 5-septate 9 per cent, 39 by 5.6 (27 to 46 by 4.2 to 6.1) ft. 

 6-septate rare. 



FROM AERIAL MYCELIUM ON STEAMED-POTATO PLUG, CULTURE II DAYS OLD 



FROM SMALL SPORODOCHIA, IN AERIAL MYCELIUM, ON STEAMED MELILOTUS STEM, 



CULTURE 51 DAYS OLD 



2-septate 2 per cent, 20 by 4.1 (16 to 23 by 3.3 to 4.6) m. 

 3-septate 65 per cent, 26 by 4.4 (20 to 33 by 3.6 to 4.7) ^l. 

 4-septate 33 per cent, 31 by 4.9 (23 to 38 by 3.9 to 5.5) m- 

 5-septate rare, 36 by 5.1 ju. 



FROM SPORODOCHIA ON STRING-BEAN AGAR, CULTURE 3S DAYS OLD 



2-septate 4 per cent, 22 by 4.4 (17 to 25 by 3.8 to 4.7) /z. 

 3-septate 56 per cent, 28 by 4.6 (22 to 38 by 3.8 to 5.2) fi. 

 4-septate 37 per cent, 33 by 4.7 (23 to 41 by 3.8 to 6) m- 

 5-septate 3 per cent, 34 by 5.1 (23 to 44 by 3.8 to 6) m- 



SUMMARY AND AVERAGE OF THESE MEASUREMENTS 



Fusariiun radicicola WoUenw. {2, 11, 14, p. 257-260, pi. 6, fig. S, text fig. 47; 21, p. 

 257-258, pi. 16, fig. K; 22, drawing 423). 



The organism isolated appeared to be identical with that originally 

 described by Wollenweber {21) and when inoculated into potato tubers 

 a typical blackrot was produced. 



