ENbDoTHrA CANKER OF CHESTNUT 591 
youngest part of the canker, and transferring it to agar tubes. Anderson 
and Anderson (1913) have described in detail various other methods of 
isolation. Either kind of spores may be sown on the agar, or streaks 
may be made on agar slants with. the spore horns, or the ascospores may 
be permitted to fall on agar plates after natural ejection. 
General cultural characters 
There are certain characters that are common to the growth of the 
organism on most of the artificial media commonly used, particularly 
the agars. 
Murrill (1906 a:146) says: ‘‘ When grown in artificial culture, the 
mycelium of the fungus is at first pure white, changing to yellow with 
age, and the fruiting pustules are a beautiful yellow.” He finds that the 
fruiting pustules are produced in eleven days, and mature spores in the 
process of discharge in twenty days. Neither Murrill nor any writer 
since 1906 has succeeded in producing the ascospore stage in culture. 
Clinton (1909:886) describes the same color change on lima-bean agar, 
and adds: ‘‘ The threads form a rather hard crust on the surface of the 
medium, and in this the Cytospora fruiting stage develops as numerous 
small elevations. The spores, after maturity, ooze out on the pustules 
as lemon-yellow drops, which later become light chestnut-brown in 
color.”’ 
Anderson and Anderson (1912 a) advocated the cultural characters 
as a means of distinguishing this species from the other very closely 
related and confusing species of Endothia. Since then, Pantanelli (1912), 
Clinton (1913), and Shear and Stevens (1913 a) have studied this phase, 
and they all find additional cultural characters on a number of media 
by which these forms may be distinguished. It is not our purpose 
to discuss these differences in this publication, since they do not 
directly concern us at this time. Only the most important characters 
that relate to E. parasitica will be mentioned. For a more complete 
discussion the reader is referred to Shear and Stevens (1913 a), where the 
cultural characters on a large number of media are described in detail. 
Stertlized twigs 
On twigs of all the common forest trees that were tried (Anderson and 
Anderson, 1912 a), the fungus produces a short, white, web-like growth 
over the surface of the twig, with heavier bunches of mycelium which 
later become orange-colored, where the pycnidia are to develop: On the 
cut ends of the twigs there is developed a thick, felt-like, orange mycelial 
growth, but this never extends out on the bark as in E. radicalis. The 
same characters were found by Shear and Stevens (1913 a), ore that 
