CULTURAL CHAEACTEES OF CHESTNUT-BLIGHT FUNGUS. 13 



as well as eailier in appearance. The high-acid media, however, gave 

 the distinctive colorations described more quickly than those of lower 

 acidity, 



CULTURES ON OATMEAL. 



The oatmeal is prepared as follows: Put 10 grams of oatmeal in 

 100-cubic-centimeter Erlenmeyer flasks. Add 20 cubic centimeters 

 of distilled water. Stir until thorouglily mixed, plug, and autoclave 

 for 25 mhiutes at 120° C. 



Starch, rice, and white corn meal are prepared in the same manner, 

 but cultures of all species developed so slowly on starch in flasks that 

 this mechum was abandoned. Corn meal in 1-inch test tubes pre- 

 pared in the same manner was tested with 10 strains of EndotJiia 

 parasitica and 30 of E. radicalis, using about an equal number of 

 American and European strains. This did not show the same color 

 reactions as in the flasks. Only about half of the tubes of E. radicalis 

 showed purple before the medium dried up. 



Endothia parasitica. — Cultures 1 week old showed a superficial, 

 more or less erect, pure white cottony growth covering the whole 

 surface of the medium. Endothia parasitica on the same medium 

 12 days old began to show spore massss extruding through the white 

 mycelium near the point of inoculation. At the end of a month the 

 spore masses, which were pale yellow ocher, were rather numerous, 

 of medium size, and scattered over the surface of the culture. The 

 older portions of the mycelium in contact with the glass were orange. 

 At 6 weeks of age cultures showed more or less sunken patches very 

 near flame scarlet, whereas cultures on other media of the same age 

 showed no change. 



Erulothia radicalis. — ^Cultures at the end of a week showed a growth 

 about as luxuriant as in Endothia parasitica, but the aerial portion 

 had a slightly coarser and more tufted appearance. The color ranged 

 from light orange yellow tlirough perilla purple to light pinkish lilac 

 at the margm. The older portion of the culture in contact with the 

 glass was perilla purple, apparently in both mycelium and medium. 

 On the same medium at the end of a month there was a somewhat 

 greater development of mycelium, with a more compact surface and 

 irregular small cusliionlike masses. The perilla-purple color had 

 almost entirely disappeared from the surface, but could be seen 

 through the oatmeal on the bottom and sides of the flask. The 

 mycelium in contact with the flask was orange. No spore masses 

 were present. 



Endothia radicalis mississippiensis . — Cultures 1 week old showed 

 a buff growth covering the surface of the medium. About three- 

 fourths of the older portions were orange chrome. The superficial 



[Cir. 131] 



