28 BULLETIN" 1380, U. S. DEPARTMENT OF AGRICULTURE 
the stems were conspicuously shrunken for a distance of 1 to 2 centi- 
meters, above which there was a slight enlargement. A zone of 
brownish mycelia encircled the diseased areas in the region of the 
enlargement. This when examined was found to be of the nature of 
an Exobasidium but too immature for determination. The brown 
strands of a Marasmius were also present. 
BLACK-BARK FUNGUS 
The species known as the black-bark fungus (Nummularia anthra- 
codes (Fr.) Cke.) was first found developing in the living bark on 
burls caused by Dendrophthora poeppigii. It was again found 
bursting through the smooth living bark above a series of old tap- 
ping cuts. The appearance of the fungus in the living bark with- 
out any previous indication of its presence is remarkable (PL XIII). 
For this reason its parasitism should be investigated. The sub- 
cortical habit between the outer bark layer and the zone of stone 
cells is characteristic and in this respect differs from the other 
species of its group found on Hevea. Other related species, such 
as Niimmiihiria cincta and a variety of N. cow/mixta, on young 
smooth trees may first develop beneath the bark epidermis, which 
is later defoliated, but they are never deep seated and are usually 
found on dead trunks or branches. 
The fungus in all probability is dependent upon wounds to effect 
an entrance in the bark. Bruises, tapping cuts, openings made in 
the bark by the sinkers of mistletoes, and insect injuries are appar- 
ently the most likely means of entrance. The bark is killed over a 
considerable area, forming cankers. On the under surface of the 
bark black lines bordering light-colored areas are formed. These 
are also found on the surface of the wood. In advanced stages the 
black lines appear in the wood, which later becomes generally dis- 
colored. 
The fungus should not be considered of much economic impor- 
tance and would undoubtedly be absent on trees under proper man- 
agement. Ridley refers to what is probably the same fungus under 
the name Eutypa caulivora*. He states that it is probably a true 
parasite and comes to the surface to fruit only when the host is 
dead. He thinks the fungus is saprophytic. Massee considered it 
certainly parasitic but without proof. Bancroft reports it as a 
wound parasite. 
Several other Pyrenomycetes were collected on the dead wood 
and bark of old tapping cuts. They were apparently saprophytic 
and may be disregarded here. They will be described in the follow- 
ing paragraphs. 
DISEASES OF TAPPING WOUNDS 
Various fungous organisms have been observed in and around 
the tissues- affected by the cuts made by the machadinho (a small 
ax) in collecting the latex. The most common were the die-back 
fungus (Diplodia), Dendrographium atrum, Stilhum (drmabarinwn, 
Nummularia cincta, N. commixta vai\, Hy poxy Ion sclerophlaeum, 
H. bipapfflatum, UstuMna and Xylaria species, Eutypa comosa, inde- 
terminate Thelephoracese, and molds. 
These organisms, with one or two exceptions, were apparently of 
little moment as regards the evident production of continuous and 
