6 4 6 
THE TROPICAL 
AGRICULTURIST. [January 2, 1882. 
planters) will have enabled their coffee to derive the full 
benefit of the nourishment elaborated in such leaves, 
instead of getting only such portion as it can share 
with the parasites when once they form a lodgment. If 
only the spore tubes are present in sufficient quantity, 
all that is wanted is moisture to germinate them, in 
order not only to infect each leaf with one or a few 
but to fill each stoma of every leaf. That is the " owre 
true tale," the moral of which we have to study, and 
in its light, surely, the dullest of lay readers can under- 
stand that manure, so far from being a cure for "leaf 
disease," is an active agent in propagating the fungus 
which is the cause of leaf disease — disturbance of those 
functions on whose regular action the plant depends for 
healthy life. But manure can only act in this way when 
spores of the fungus are allowed to exist and obtain 
access to the leaves of the plant. Were the spores de- 
stroyed or prevented from obtaining access to the sap- 
cells of the leaves, then, as in the pre-fungus era, the 
whole benefit of the manure applied to the root of the 
tree would go first to the formation of nutriment in 
the leaves and then to the perfecting of a profitable 
crop of fruit. The planter's great duty then is, by all 
means within his reach, to destroy spore-infected leaves 
and twigs by burning or burying them. If buried, of 
course they should be thoroughly covered with quick- 
lime ; and a portable incinerator, which we have heard 
of as manufactured for a planter by Messrs. John Walker 
& Co., which can be easily carried from place to place 
by a couple of coolies, may help to solve the problem 
of how, at a reasonable cost, to destroy refuse leaves, 
twigs, &c. Then shelter shoidd be conserved or supplied 
to prevent the wind blowing the spores on the leaves 
of the coffee trees. If all this is done, then certainly 
even Mr. Ward would admit that manure might prove 
a cure for " leaf -disease " — not of the cause, Hemileia 
vastatrix, but the effect, debility superinduced by re- 
peated visits of the voracious parasite to the life-sup- 
plying laloratory of the plant, contained in its foliage. 
But, if nothing is done : if neither burying nor burning 
is resorted to, if shelter is not provided, and if spores 
on the leaves are not lulled by sulphurous gases before 
they germinate and enter the stomata, then manuring 
must be resorted to, even at the risk of propagating the 
fungus, because it is better to manure so as to foster ■ 
fungus, plus leaves and fruit, rather than abstain from 
manuring at the risk of seeing tree, foliage and fruit 
becoming " small by degrees and [not] beautifully less," 
from the persistent presence and destructive effects of - 
the fungus. To give up manuring would be to throw 
up the sponge and confess ourselves hopelessly beaten 
in the contest ; but clearly oiu- duty is if possible to 
follow Mr. Ward's advice and apply manure as a com- 
plement to operations calculated to annihilate or reduce 
to the smallest minimum those fungus spores, which, if 
present, would, in proportion to their number, deprive 
the coffee of the life sap elaborated in the leaf cells as 
the result of an application of manure. Hemileia vast- 
atrix, ho far from being the external development of 
an "internal ulcer," its an authority highly honoured 
by a certain sapient judge explicity taught, is so essenti- 
ally an external agent, that its spores might, for an in- 
3efinite period, be scattered over the leaves of a coffee 
(nc, without producing the slightest ill effects, provided, 
the spores did not receive moisture to germinate them 
and enable them to enter the leaves by the mouths on 
their lower surface. The spores and the favourable con- 
ditions present, no condition of a tree can enable it to 
resist an attack, while no predisposition will intensify 
that attack. Once for all, planters, and critics of plant- 
ing operations, may dismiss from then minds all ideas 
of " leaf -disease " having been caused by errors in de- 
tails of cultivation or the constituents of manure. But 
for the mysterious development in 18G9 of a parasite 
which had been previously latent, leaf-disease (the effect 
j of the parasite's operations) would be non-existent, and 
the majority of our coftee estates woidd be still yield- 
ing average crops of 6 cwt. per acre or even more. 
Our one error, as we now can see, was the very natural 
one of growing in large and unbroken areas, to the 
almost total exclusion of other products, that which paid 
the cultivator best : that which gave the largest and the 
most profitable returns. That was the principle on which 
potatoes were so largely grown in Ireland and other 
places, and that is the principle on which wheat is grown 
in America and Australia ; tobacco in Sumatra ; sugar 
in the West Indies, Java, &c. When visitations of pro- 
vidence, in the shape of ; disastrous natural agencies, con- 
vey sharp lessons, then some - of us can loudly condemn 
what their neighbours and even they themselves did, as 
unscientific and even immoral. As far as Ceylon coffee 
planting is concerned, all we can say is that unless we 
are suffering for the one error we have mentioned, or 
unless special chastisement has come upon us for special 
sins, we do not feel that planters are to blame. On 
most of the estates, all that capital and labour, care 
and skill, and scientific appliance, could effect was done 
to keep the soil in heart while it yielded remunerative 
crops. When Skobeloff had a great disaster inflicted on 
him, he said: "I blame no one: it was the will of 
God." So, without irreverence, we think we may assume 
that it was the will of providence that the great and 
once ■ prosperous coffee enterprise of Ceylon and the 
Eastern world should be checked (we cannot and will 
not say destroyed) by the development of a new and 
terrible parasite. The plague having existed and oper- 
ated injuriously for a considerable period of years, may 
we not cherish the hope that the time for its gradual 
lessening in virulence, if not its entire disappearance, is 
close at hand. Perhaps the theory of " cycles " may 
not be deemed scientific or worthy of regard by the 
school to which Mr. Marshall Ward belongs, but surely 
he must have at least adverted to the idea of the pest 
passing away with effluxion of time. Is there anything 
in the nature of Hemileia vastatrix, or in the analogy 
of like pests, to render the hope of its virtual dis- 
appearance within a few years unreasonable? 
BEMILE1A VASTATRIX AND COFFEE LEAF- 
DlSliASE : Mil MARSHALL WARD'S REPLY 
TO CRITICISMS ON HIS REPORTS. 
(To the Editor, "Ceylon Observer.") 
Dear Sir,— In replying to Mr. Talbot's criticism 
on my third report on coffee leaf-disease, I propose to 
consider at the some time some of the various oth r 
remarks which have been mad", both in private letters 
and in the newspapers, and which must be looked 
upon as adverse to proper views of ihe nature of this 
"disease": this I do the more readily, since a few 
