ENDOTHIA PARASITICA AND RELATED SPECIES. 37 



have grown the organisms on sterile twigs of many species and on 

 liquid media. 



As stated above, the various species of Endothia are distinguish- 

 able on any medium tested. White corn meal in flasks has, however, 

 been most used by the writers in identification work and for keeping 

 stock cultures. All the species grow readily on this medium and may 

 be determined with certainty within 10 days under ordinary con- 

 ditions of growth. In addition, the medium is cheap, easily pre- 

 pared, and does not dry out so quickly as agar media in tubes, so 

 cultures may be kept alive much longer without transfers. Almost 

 equally good for purposes of identification are rice and oatmeal in 

 flasks, corn-meal agar, and potato agar. 



The distinguishing characteristics of the various species in culture 

 have been described rather fully in the previous publication and may 

 be briefly summarized, as follows: 



CULTURES ON CORN-MEAL AGAR (UNSLANTED TUBES). 



Corn-meal agar proved the best agar medium for the production 

 of pycnospores and showed constant differences in the cultural 

 characters of the various species. The most characteristic differences 

 appeared in cultures from six to eight weeks old on unslanted 

 tubes. (See PL XXI, figs. 2 to 7.) 



Endothia gyrosa at this age showed a rather abundant, felty white myce- 

 lium, flecked with capucine buff, but there were no pycnidia. In older cul- 

 tures small pycnospore threads were sometimes produced. Usually before the 

 cultures were 10 days old the medium was changed to a delicate lavender 

 just below the mycelium, and below this to a light olive green. A few days 

 later the lavender disappeared and the green deepened to olive green. 



Endothia singularis grew more slowly than any other species. Within 

 three weeks, however, the mycelium covered the entire surface. It was 

 smoother than E. gyrosa and nearly white, with raw umber spots where the 

 mycelium touched the glass. The medium was changed to a light hellebore 

 green one-half inch below the top. 



Endothia fluens, as pointed out in the previous paper, produced an abundant 

 deep-chrome mycelium, with usually one or two rather small pycnidial pus- 

 tules. 



Endothia fluens mississippiensis produced a scant surface growth of my- 

 celium, between cadmium yellow and raw sienna in color. The upper one-half 

 centimeter of the agar became reddish orange. The pycnidial pustules were 

 more numerous than those of E. fluens, but smaller and more scattered than 

 those of E. parasitica. 



Endothia longirostris at the end of six weeks had a scant, webby, orange, 

 aerial mycelium growing against the glass. Mycelium on the surface of the 

 medium was very scant, orange to cadmium yellow in color, with scattered tiny 

 xanthine orange to orange spore masses. The color of the agar changed to 

 medal bronze just beneath the mycelium, shading into orange citrine below. 



Endothia tropicalis at the end of six weeks showed a thinly felted mycelium, 

 white to capucine orange, with numerous small, scattered pycnidial pustules. 

 The ring of mycelium against the glass was light orange yellow, as contrasted 

 with white in E. parasitica. 



