16 CIRCULAR NO. 131, BUREAU OF PLANT INDUSTRY. 



Endothia radicalis. — Cultures at the ago of 1 week showed a growth 

 of loose, fluffy mycelium covering one-half the surface of the medium. 

 The growth was less in quantity and also less compact than that on 

 rice and oatmeal. The same colors were present as in the cultures 

 on rice, but paler. No spores were present. 



Cultures 1 month old showed a compact growth with a nearly 

 smooth surface. The color ranged from light cadmium to empire 

 yellow. The whole mass of the medium was pcriila purple. No spore 

 masses were found. 



• Endothia radicalis mississippiensis. — Cultures 1 week old showed a 

 growth very similar to that on oatmeal, but less in extent and in 

 aerial development. The color of the mycelium was orange chrome. 

 There was no discoloration of the medium, and no spore masses 

 were found. 



The same form of the fungus from the same source 1 month old 

 produced a growth with a compact, rather uniform surface, the super- 

 ficial portion having a coarse, matted, webby appearance, which was 

 most noticeable about the margin. The color of the mycelium was 

 cadmium orange to xanthine orange, while that of the medium was 

 unchanged. Spore masses were much more numerous than in Endo- 

 tliia radicalis, but smaller and less numerous, though very similar 

 to those of E. parasitica. 



Endothia gyrosa. — Mycelial cultures 1 week old showed a growth 

 practically the same in quantity as in Endothia radicalis but more 

 compact on the surface and ochraceous buff near the point of inocu- 

 lation, shading into white at the margin. There was no discolora- 

 tion of the medium, and no spore masses were seen. 



Cultures of the same kind 1 month old showed an abundant, 

 rather thick growth, having the surface mostly covered with somewhat 

 irregular tubercular masses of mycelium, suggesting immature 

 pycnidial stromata similar to those formed in Endothia radicalis, 

 but smaller and producing no spores. The surface of the culture was 

 capucine buff. The surface of the tubercles was honey yellow to 

 Isabella. The dark color was apparently due in part to numerous 

 superficial water drops. A portion of the medium was perilla purple. 



Aside from the differences in color, the most conspicuous and im- 

 portant characteristic of these fungi in corn-meal cultures is found in 

 the fructification. Clinton has already mentioned and illustrated 

 similar differences in cultures of these organisms on agar in Petri 

 dishes. In Endothia parasitica the pycnidia and spore masses are 

 small, numerous, thickly scattered, and embedded in the mycelium. 

 E. radicalis, on the other hand, forms but few large, erumpent stro- 



[Oir. 131] 



