2 
able numbers. The diseased trees usually occur in groups, the 
infection spreading slowly but in constantly widening circles. An 
examination of dying trees shows the roots to be badly rotted, 
Their surface tissues are invaded by a white fungus mycelium 
that is usually more abundantly developed in the space between 
the bark and the wood. The disease seems first to attack the 
smal! rootlets, gradually spreading to the larger roots and to the 
crown, when the tree dies. In many cases seemingly healthy 
trees near the borders of infested areas were found to have the 
roots on the side next the dying trees badly diseased, while on 
the other side they were still perfectly healthy. The fungus seems 
to be the mycelium of some one of the Hymenomycetes. Numer- 
ous species of Polyporaceae and Thelephoraceae were found on 
logwood stumps and logs, but in no case could their connection 
with this root rot be satisfactorily proven. Whatever the nature 
of the fungus, leaving stumps of trees that have died from this 
disease in the neighborhood of living trees is clearly danger- 
ous. Dying trees should be dug out and the roots burned 
as soon as the disease can be detected. Where it is con- 
fined to certain small definite areas, as is often the case, it would 
be advisable to dig a trench three feet deep just outside of 
the diseased area in order to prevent its spreading underground 
to the roots of healthy trees. On a few of the estates examined 
the disease was so widely scattered that this method of treatment 
would not be practicable. Here it would seem best to clear the 
infested tract entirely of logwood, marketing such as was suffi- 
ciently mature and allowing the land to grow up in pimento and 
limes or reserving it for pasturage or cultivation. It should be 
mentioned in this connection that pimento trees are said to die 
from a similar root rot in some parts of the island. If this should 
prove to be identical with the logwood root rot, pimento would 
not be available as an alternative crop. 
This root rot seems to spread slowly. One old logwood 
chipper assured me that trees had been dying for thirty-five years 
on a spot that he pointed OuE This area does not now include 
over three oF four acres. This would indicate that by vigorous 
measures it could be controlled. The disease was found on 
