40 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



Endothia fluens mississippiensis. — Cultures one week old showed an orange- 

 chrome growth a little more than half covering the surface of the medium. 

 The superficial growth was very similar to that of E. parasitica. There was no 

 discoloration of the medium and no spore masses were found. 



The same organism one month old produced a growth with a compact, rather 

 uniform surface, the superficial portion having a coarse, matted, webby appear- 

 ance, which was most noticeable about the margin. The color of the mycelium 

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

 changed. Spore masses were much more numerous than in E. fluens, but 

 smaller and less numerous though very similar to those of E. parasitica. 



E. longirostris. — Cultures one week old covered about one-third of the sur- 

 face of the medium. The mycelium was short, fluffy, white, with only a tiny 

 spot of cadmium orange near the point of inoculation. At the end of six weeks 

 the entire surface was covered with a compact growth rather uniform in tex- 

 ture, cadmium orange to xanthine orange in color. The surface was irregularly 

 ridged, giving it a wrinkled appearance, with tiny mars orange spore masses 

 irregularly scattered over the surface. This species closely resembles E. fluens 

 mississippiensis on this medium, being distinguished from that variety by the 

 smaller and much less numerous spore masses. The medium is changed to 

 amber brown just below the mycelium, shading into mars yellow in the lower 

 portions. 



Endothia tropicalis. — At the end of one week this showed less growth than 

 either E. parasitica or E. fluens, covering about a third of the surface. The 

 mycelium was matted close to the surface and was a very pale buff (paler 

 than any of the buffs shown in Eidgway). Xo pyenidia were present. 



At the end of one month's growth the surface was entirely covered with 

 a closely felted mycelium and small, numerous, thickly scattered spore masses, 

 more closely resembling those of Endothia parasitica than any other species. 

 The mycelium was orange buff to apricot orange, and orange chrome against 

 the glass. The color of the medium was unchanged. 



Endothia parasitica. — In cultures one week old the growth on corn meal 

 covered about one-half of the surface of the medium. The outer margin was 

 pure white, the remainder buff yellow below, with a superficial white growth 

 above. A few small pustules with spore masses occurred near the point of 

 inoculation. The medium was uncolored. 



Cultures one month old showed a compact growth, nearly smooth on the 

 surface. The superficial mycelium was pale orange yellow. The pale yellow- 

 ocher spore masses were minute, very numerous, and nearly covered the sur- 

 face. The medium was slightly greenish about the sides of the flask just 

 beneath the mycelium. 



DISTINGUISHING CHAEACTEES OF THE VAEIOF/S SPECIES ON COEN MEAL IX FLASKS. 



The color reactions of the various species on corn meal are very 

 striking. Endothia fluens (PL XXI, fig. lb), as noted above, 

 changes the whole mass of the medium to perilla purple in less than 

 a month. E. gyrosa and E. singular is also produce this color change, 

 but somewhat more slowly. E. fluens mississippiensis, E. tropicalis. 

 and E. parasitica, on the other hand, in hundreds of cultures have 

 wholly failed to produce any purple color. This furnishes an easy 

 and reliable method of distinguishing E. parasitica from E. fluens 



