KUBBER (HEVEA) DISEASES 15 
were infected some 3 or 4 feet above the ground, the fungus is 
primarily confined to the roots. 
The fungus spreads to Hevea from jungle stumps and logs. It 
is obviously necessary to free an estate of these sources of infec- 
tion and to remove Hevea stumps and logs after thinning. Once 
the disease is detected the areas of infection on individual trees 
should be divested of the affected tissues and the cavity thoroughly 
treated with coal tar. This method is usually effective in the treat- 
ment of such fungi and prevents the development of the fructifica- 
tions. Infected trees of long standing should be removed. 
All the collections of Ustulina sonata were made from trees grow- 
ing on high well-drained soil. Whether this is a condition favor- 
able to the development of the fungus further studies will deter- 
mine. It is to be remarked, however, that U. vulgai^is, the form 
which in the Temperate Zone is the cause of root-rot in various 
trees, especially maple, is usually associated with dry sites. 
Another species of Ustulina found on Hevea roots differed in 
several details from the type form of U. sonata. It was found on 
living roots of a Hevea stump. Xot until it is possible to make 
more extensive studies can its identity be determined. It is chiefly 
characterized by a conspicuous white thick subiculum (PL VIII, B). 
It is described in the mycological section of this bulletin (p. 94). 
On dead wood of wounds of different kinds, chiefly fire scars and 
areas of the trunk killed by borers, three species of related genus 
are occasionally observed. Their action and its effects upon the tree 
are similar to those of Ustulina zonata except that they do not appear 
to encroach upon the living parts of the tree as vigorously as this 
species. These fungi are Kretzschmaria coenopus (PI. IX, A), K. 
lichenoides (PI. IX, B). and K. apoda (PL IX, C). The mature 
fructifications may be mistaken for Ustulina, but they may be distin- 
guished by their structure and mode of development. Instead of 
developing as a flat disk attached at one point several anastomosing 
stalks appear. These broaden out at their apices into flattened heads, 
which later fuse with each other, forming cushions the surface of 
which is made up of small polygonal areas. These cushions are 
from 1 to 5 centimeters thick. "When broken apart the anastomosing 
stalks and individual heads are exposed. The ostiola, or openings to 
the cavities or perithecia embedded in the head, are visible on the 
surface. The young interlacing stalks and likewise the immature 
cushion are grayish white, but the entire structure becomes black and 
brittle when mature. The fungus produces black lines in the wood, 
but these are usually not as conspicuous as is the case in Ustulina. 
Kretzschmaria apoda (PL IX, C), found once on an old tapping 
wound, is distinguished from the other two species by the formation 
of larger polygonal areas and a more robust structure in general. It 
is a wound fungus and was confined in this case entirely to the dead 
wood. 
SPHAEROSTILBE REPEXS 
The fungus SphaerostUbe repens Berk, and Br., originally reported 
from Ceylon in 1907. which has been repeatedly considered the cause 
of a root disease of Hevea. tea. and other plants in the Orient, has not 
been found for a certainty on Hevea in the Amazon Valley. A dis- 
eased root of Hevea was examined which showed evidences of the 
