y Borer
again and again, and will eventually be killed.

I turn, lastly, to the consideration of a disease in coffee which is
popularly known by the name of rot, and scientifically as _pellicularia
koleroga_, a fungoid plant which crawls over the leaves and seals up their
breathing pores, till at last the leaf dies, as man does, from want of
breath. On one of my estates we have had a considerable experience of it,
and, whatever may cause rot, I feel sure that what aggravates it, and
causes it to be very injurious, is the want of free circulation of air
over the land, and through the coffee trees; and I am the more convinced
of this because we have found rot worse in the open, and where there was
little undecayed vegetable matter present in the soil, than in rather
thick shade with abundance of undecayed vegetable matter on the surface.
But in the latter case the land is on a rather high ridge exposed to the
constant winds of the south-west monsoon, while in the former case the
land was in a hollow under a hill which lies between it and the west--a
hollow completely sheltered from the wind. And it is in such sheltered
spots that we find rot worse, and quite independently of the presence or
absence of shade or of vegetable matter lying on the land. To check rot,
then, the free circulation of air is necessary both over the land and
through the plant. Much may be done in the first case by judiciously
opening channels for air through the shade trees so as to admit a free
circulation of air into hollows, and much in the latter by freely handling
out the centres of the trees which, in the monsoon, and especially in
hollows, are apt to grow a superabundance of young wood, which chokes up
the centre of the tree and thus hinders the free circulation of air. The
soil, too, is often excessively saturated in these hollows, and, where
this is the case, the land should be surface drained. Though I have not as
yet adopted the plan of sweeping up and putting into the manure heap, or
burying with a little lime added, the numerous dead leaves that are apt to
drift into hollows, I feel sure that either of these plans would be
attended with advantage, by lessening damp, and allowing a free
circulation of air over the land. I am confident, I may add here, that the
removal of the lower branches of the coffee trees, branches which in any
case bear hardly anything in well-shaded land, would be of great advantage
in lessening the damp in the plan