Apr. 8, 1918 Relation of Soil Fungi to Potato Diseases 85 



12 by 3.2 (10 to 17 by 2.8 to 4.5) ju; macroconidia in aerial mycelium, 

 pseudopiomiotes, and sporodochia, slightly curved, typically broader 

 at the middle and in the upper half of their length, somewhat abruptly 

 constricted toward the apex, slightly pedicillate, typically 3- and 4- 

 septate, the 3-septate averaging 29 by 4.2 (19 to 41 by 3.5 to 5.5) fi, 

 the 4-septate averaging 33 by 4.6 (26 to 46 by 3.6 to 5.7) /j., sometimes 

 2-septate, i - and 5-septate rare ; aerial mycelium typically well developed, 

 white; sporodochia and pseudopionnotes, light salmon-orange to salmon- 

 orange on most media, salmon-orange to old rose on Irish potato agar 

 with 10 per cent of glucose; substratum but slightly discolored or not at 

 all, slight-yellow modification on steamed rice; flesh colored to pinkish 

 wartlike plectenchymic bodies often abundant, especially on steamed 

 meUlotus stems; sclerotia often present, dark blue (on steamed potato 

 media); chlamydospores usually present in old cultures, but never 

 abundant, intercalary in the mycelium. 



Habitat: Isolated three times from Idaho soils as follows: Once each 

 from samples 2 and 3 and once from group A. Attempts to induce 

 decay in Irish potato tubers by inoculating with this organism were 

 unsuccessful. 



The conidial measurements on various media are as follows: 



CONIDIA FROM SPORODOCHIA ON STEAMED MELHvOTUS STEM, 19 DAYS OLD 



o-septate i per cent (immature, about same as 3- and 4-septate). 

 2-septate 5 per cent, 18 by 4.3 (15 to 22 by 4 to 5) /u. 

 3-septate 50 per cent, 31 by 4.7 (23 to 36 by 3.5 to 5.5) fi. 

 4-septate 41 per cent, 35 by 5.2 (28 to 39 by 4.3 to 5.7) /x. 

 5-septate 3 per cent, 36 by 5.7 (28 to 40 by 4.2 to 5.7) n. 



CONIDIA FROM AERIAL MYCELIUM ON STEAMED MEULOTUS STEM, 21 DAYS OLD 



Microconidia: 



o-septate 14 per cent, 8 by 2.2 (7 to 11 by 2 to 2.8) /x- 



i-septate 11 per cent, 13 by 3 (10 to 14 by 2.8 to 3.6) ix. ^ 



Macroconidia: 



2-septate 3 per cent, 19 by 3.5 (18 to 21 by 2.8 to 3.6) /x. 



3-septate 68 per cent, 28 by 4.2 (21 to 32 by 3.6 to 4.5) n. 



4-septate 4 per cent, 32 by 4.5 (28 to 36 by 4.3 to 5) /u. 



5-septate rare (only one observed) 35 by 5 /j.. 



CONIDIA FROM SPORODOCHIA ON STEAMED POTATO-TUBER PLUG, 49 DAYS OLD 



2-septate i per cent, 19 by 4.2 (16 to 22 by 4.3 to 5) fx. 

 3-septate 51 per cent, 30 by 4.3 (21 to 35 by 3.8 to 5) yu. 

 4-septate 48 per cent, ;^:^ by 4.5 (26 to 41 by 4 to 5) ix. 

 5-septate rare (only one observed) 34 by 5.1 m- 



CONIDIA FROM PSEUDOPIONNOTES ON STEAMED POTATO-TUBER PLUG, 20 DAYS OLD 



O-septate i per cent, immature, 

 i-septate rare, 20 by 4 (19 to 26 by 3.5 to 4.5) fx. 

 2-septate i per cent, 22 by 4.5 (20 to 26 by 3.8 to 5.0) /x. 

 3-septate 68 per cent, 30 by 4.3 (21 to 36 by 3.6 to 5) fx. 

 4-septate 30 per cent, 33 by 4.6 (29 to 41 by 3.6 to 5.7) /x- 



