8 THE COCCUS OF THE COFFEE-PLANT. 
underside of their leaves, their stomata, or breathing-pores, are shut 
up, and death is the consequence. 
Fumigation with sulphur has been recommended, but not yet, so far 
as I know, put to the test of experience in Ceylon; and some experi- 
ments which I am at present instituting with tar-water are not suf- 
ficiently advanced to be detailed. 
_ Tt is, however, very doubtful if any remedy will ever be discovered 
sufficiently cheap, and, at “the same time, easy of ‘application on the. 
large scale which Coffee estates require. The hot-houses of England 
have long been infested by more than one species of Coccus; and 
. powders, washes, and fumigations of all kinds have been again and 
again prescribed for their destruction, but seemingly without effect, 
as I find that Loudon, in his * Encyclopedia of Gardening’ (5th 
edition, p. 431), concludes an article on this subject in the following 
words :—** Brushing off these creatures is the only effectual remedy, 
and, if set about at once and persevered in, will save the trouble 
of many prescribed washes and powders, which are mere palliatives.” 
This measure, of course, is out of the question on a Coffee estate, 
unless, indeed, while the pest is still in its infancy ; but the productive 
powers of the insect being so great, and the means of spreading the 
infection so numerous, it is to be feared that such a plan would soon 
be found to be impracticable. 
From all I have seen of the nuisance, I am inclined to believe that it 
is not under human control ; and that, if ever it disappears from the 
island, or at least becomes so much lessened in its effects as to be 
productive of but little injury to estates, it will be by running itself 
out, which blights of a somewhat similar nature have been known to do 
in other countries. Whether this will prove to be the case with the 
Coceus of the Coffee is unfortunately the less to be expected, as the 
experience of the last five years goes far to prove its permanency. I have 
the honour to be, Your most obedient servant, - 
^». GEORGE GARDNER, F.LS., 
Superintendent of Botanical Garden. 
References to the Plate, TAB. XH, . d 
l. A branch of the Coffee-tree, infested by the Coceus, with the back 
of a leaf covered in the middle with the male insect, and a few 
matured females on the margin :—nat. size, | 
