1898 ] THE DEVELOPMENT OF SOME ANTHRACNOSES 93 
a pure white, with a later development of sepia colored stroma 
over the central portion, where the fruiting pustules are most 
abundantly developed. This portion of the colony is not con- 
fined to such a limited area as it is in colonies of Col. dagenarium ; 
nor does the outer portion of the colony become tinged, but 
remains a distinct white. 
On bean stems the stroma is also soon developed, causing 
a blackened appearance of the stems, upon which there is but 
slight mycelial development, but it forms a white mat over the 
surface, which for some time forms a marked contrast to the 
blackened stems. In cultures a month old this also develops a 
stroma. ; 
Since making the original parallel cultures the two species 
have been subsequently studied in connection with others; and, 
from material collected at different times and localities, with 
uniform results. The colonies of the bean anthracnose leave the 
impression of a study in black and white, while that of the 
watermelon, one in pink or salmon and a dark reddish-brown. 
A comparison of the two is well shown in figs. 77, ré, 10; 
20, 
These various differences which are so marked, and which 
are quite constant under varying conditions of temperature, 
seem to show conclusively, notwithstanding previous results in 
inoculation, that the two are distinct species. 
From experiments made by the writer, it would seem that 
very little dependence can be placed upon the results obtained 
from cross inoculations made in the laboratory. The host to be 
inoculated is placed in a moist chamber or under a bell jar, where 
the moisture of the fruit is conserved, and the conditions are 
then favorable for any fungus which is already lurking in the 
tissue to develop. On the other hand, it has been shown that 
the fungi of this group easily adapt themselves as saprophytes, 
and a watery fruit like the watermelon or citron, which has been 
separated from the plant, has lost to a degree the power of 
resistance, and becomes more or less of the nature of a culture 
medium. 
