ENDOTHIA PARASITICA AND RELATED SPECIES. 39 



E. tropicalis covered the entire surface with a thin layer of surface mycelium, 

 considerably darker in color than when one week old. 



Endothia parasitica. — At the end of three or four days at room temperature 

 this showed a short, fluffy, white, aerial growth along the streak. The surface 

 of the mycelium was orange by transmitted light, while by reflected light it was 

 between raw sienna and antique brown at the sides. Within six days the 

 mycelium, especially at the base of the agar slant, took on a peculiar metallic 

 " brassy " appearance, due apparently in part to the character of the mycelium 

 and in part to the minute water drops scattered over the surface. This 

 portion of the culture was light orange yellow by reflected light and orange 

 by transmitted light. This metallic appearance has been found to be the 

 most constant and reliable distinguishing character of E. parasitica on potato 

 agar. In 12 to 14 days small pycnidial pustules appeared in the upper portion 

 of the tubes, and the agar just below the mycelium became warbler-green, 

 changing later to olive green. 



CULTURES ON CORN MEAL (IN 100 C. C. ERLENMEYER FLASKS). 



Endothia gyrosa. — Mycelial cultures one week old showed a growth of rather 

 compact mycelium covering nearly one-half the surface of the medium. The 

 mycelium was ochraceous buff near the point of inoculation, shading into 

 white at the margin. There was no discoloration of the medium and no spore 

 masses were seen. 



Cultures of the same kind one month old showed an abundant, rather thick 

 growth, having the surface mostly covered with somewhat irregular tubercular 

 masses, suggesting immature pycnidial stromata similar to those found in 

 E. radicalis, but smaller and producing no spores. The surface of the culture 

 was capucine buff, that of the tubercles honey yellow to Isabella. The dark 

 color was apparently due in part to numerous superficial water drops. A por- 

 tion of the medium was changed to perilla purple. 



Endothia singularis. — Mycelial cultures one week old covered only one-third 

 of the surface. The growth was mostly white and fluffy, with ochraceous buff 

 near the center. 



At the end of one month the growth had entirely covered the surface. The 

 mycelium varied in color from cadmium orange to capucine buff, the color being 

 distributed over the surface in patches. The corn meal was changed to perilla 

 purple near the center. No spores were produced. 



E. singularis was readily distinguishable from E. gyrosa, which it resembled 

 more closely in culture than any of the other species, by the rate of growth and 

 the color and nature of the surface of the mycelium. E. singularis grew more 

 slowly than E. gyrosa, was rather brighter in color (cadmium orange), and 

 the surface of the mycelium was decidedly more even, lacking the tubercular 

 masses characteristic of E. gyrosa. 



Endothia fluens. — Cultures at the age of one week showed a growth of 

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

 mycelium was deep chrome to light orange yellow at the point of inoculation, 

 passing through perilla purple and light pinkish lilac and fading into white at 

 the margin. Occasionally the medium was changed to perilla purple near the 

 center. No spores were present. 



Cultures one 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 perilla purple. Spore masses were rarely present at 

 this stage, but shortly afterwards a few large erumpent stromata were formed, 

 which extruded spores in thick masses. 



