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



Endothia fluens mississippiensis. Growth slightly less abundant than in 

 E. parasitica; submerged except at the very edges ; much lighter in color, being 

 reddish brown. 



Endothia tropicalis. This differed markedly from either E. parasitica or 

 E. fluens. The mycelium formed a thin felt over the surface, white to salmon 

 orange in color, with no change in the medium. 



Endothia parasitica. Mycelial growth very abundant, closely matted, chiefly 

 submerged, but slightly arborescent in one or two small areas, which remained 

 above the surface. Color, dark greenish brown. 



CULTURES ON STERILIZED TWIGS (IN TUBES). 



Early in this work it was notec^ that all the species of Endothia 

 grew readily on sterilized chestnut twigs in test tubes. Later, tests 

 were made with twigs from a number of common, woody plants. 

 Twigs of Acer saccharum, Alnus rugosa, Betula papyri/era and B. 

 lenfia, Carpinus caroliniana, Cornus florida, Fagus grancfifolia, 

 Fraxinus americana, Ostrya virginiana, Populus grandidentata, 

 Prunus serotina, Rhus glcibra, Tilia americana, and Tsuga canadensis 

 were collected in New York State early in June, placed in test tubes 

 with a few cubic centimeters of distilled water and sterilized in an 

 autoclave. All the species of Endothia were tested, and all grew on 

 every species of twig except Tsuga. The difficulty of completely de- 

 scribing this series may readily be seen from the fact that each species 

 of Endothia had a different appearance on every kind of wood. 



In general it may be stated that Endothia gyrosa and E. singularis 

 grew more slowly than the other species and produced no spores, 

 while all the other species produced spores on most hosts. The 

 mycelium of E. parasitica was usually white,. especially on the bark. 

 E. gyrosa and E. singularis produced various shades of buff, while 

 E. fluens, E. fluens mississippiensis, and E. tropicalis developed a 

 much more brightly colored mycelium, usually showing yellow or 

 orange shades. 



MOISTURE RELATIONS. 



In an earlier paper (77, p. 7) the writers reported tests with 

 Endothia fluens and E. parasitica on media containing various per- 

 centages of water. It was observed that pycnospore production 

 began earliest and was most abundant on the media containing the 

 least moisture. 



Aside from this the writers have thus far been unable to make 

 definite tests as to the moisture relations of these fungi. However, 

 incidental observations in connection with the light tests (p. 43) and 

 temperature tests (p. 45), as well as results of field experiments, 

 particularly those at Woodstock, N. Y., make it apparent that the 

 amount of available moisture is a very important factor in the 

 fructification of the fungus. 



