HOESE-HAIR BLIGHTS. 
55 
Marasmius obscuratus Berk. 
Another species of Marasmius with similar mycelium has 
been found in the jungle at elevations from 400 to 2,000 feet. 
Its mycelium is dull black, and more rigid and thicker than 
that of Marasmius equicrinis. It differs, too, in habit from the 
latter species. In general, it keeps near the ground, not 
ascending higher than about 3 feet. Its cords may be 
long when they are attached to living bushes, but it is more 
frequently found running over dead branches or twigs near 
the ground, and in that case the cords are only 10 to 20 
centimetres in length. Apparently it does not attach itself 
to leaves. 
The mycelium is cylindric, 0 * 4-0 • 6 mm. in diameter. When 
it comes in contact with living branches, it fixes itself 
to them by rather large cushions of brown or white hyphæ, 
which penetrate into the plant and ultimately kill the branch . 
x\s a rule, the mycelium does not grow along a branch, but 
across it. But when it meets a dead branch, either on a bush 
or on the ground, it disappears into the dead tissue and breaks 
out again some distance further along the latter. Conse- 
quently the tangle on the ground and in the lower parts of the 
bushes consists of dead twigs united by short lengths of rigid 
black mycelium. The mycelium within the dead twig is 
normal ; the black rhizomorphic cord breaks up into separate 
hyphæ when it enters the host tissues. On specimens kept 
in the laboratory the growing point bore a subglobose, white 
tuft of hyphæ, but this has not been Observed in the field. 
A tangle of mycelium and dead tAvigs was kept on damp 
soil under a bell-glass for nearly a year. At first it produced 
only long free strands of mycelium. At the end of nine 
months several specimens of a Marasmius appeared on the dead 
twigs, but as they were not connected with the black mycelium 
it was thought that they might be intrusive. A month later, 
hoAvever, the same Marasmius developed on the black 
mycelium. 
The pileus is hemispherical, umbilicate, up to 1 cm. in dia- 
meter, usually with the margin narrowly re-curved. Some 
specimens become infundibuliform. It is plie ato-sulc ate 
almost to the centre. In the umbilicus it is dark brown, 
