506 
THE TROPICAL 
AGRICULTURIST. [December i, 1881. 
one to expect that it is in this direction that the 
principal relief is iikely to be found. We may surely 
now well reject all notions of " cures " and specifics. 
" Prevention is better than cure " is an old adajie, 
and with our new vantage ground of knowledg" of the 
extremely short period during which it is possible to 
get at the parasite at all, the short life of each 
individual -ffe;«;7e<'«-plant, and the frequency and want 
of periodicity (in the almanac sense) in the attacks 
of the disease, it may well be doubted whether so 
much benefit is to be obtained by never-ending 
attempts to check each attack, as by a general com- 
bination to destroy spores and hinder their disper- 
sion. I would particularly call attention to the 
experiments with lime and sulphur made by Mr. 
Anton at Harrow— in their careful accurary models 
worthy of imitation of the mode in which such should 
be conducted — as illustrative of the temporary nature 
of the benefit obtained at so large an expense. 
4. The only other course is by careful cultiva- 
tion, judicious manuring, and attention to the indivi- 
dual trees, so to improve the coffee as to enable it to 
endure the disease, produce fresh leaves, and bear 
a larger crop ; but Mr. Ward properly points 
oat that the benefit so obtained is not due to lessening 
in any degree leaf-disease ; the parasite indeed is 
likely to be increased rather than diminished. 
5. On the whole, lam convinced that the possession 
of this clear and connected history of the disease of 
the coffee-leaf in Ceylon is a great gain, and has given 
us a largely increased chance of dealing with its 
ravages. 
6. As I have been requested by you to offer my opi- 
nion as to the desirability or otherwise of the Crypto- 
gamist's appointment being continued over a third year, 
I have, in concert with Mr: Ward himself, considered 
carefully the present position of the enquiry from all 
points of view. I may say at once that Mr. Ward 
looks upon the present report as final in its character, 
and does not anticipate that any discovery of practical 
value would result from further work at Hemileia. 
Indeed the only point of any importance remaining 
unsolved is the history of the second kind of spore to 
which attention was called in the last report. To that 
nothing can yet be added. From the purely scientific 
aspect of the enquiry, further information on 
this matter would doubtless be of considerable interest, 
but any practical bearing of the discovery af a second 
host-plant for the fungus is rendered unimportant, 
since the ordinary mode of its direct dissemination by 
the yellow uredospores has been so completely demon- 
itrated. The Cryptogamist does not consider that 
another year's sojourn in Oylon would be profitably 
spent either to the Colony or to himself in this search, 
which would be possibly futile (since the discovery of 
such a plant, if it exist here, is greatly a matter of 
chance), or, if successful, offers so slight a probability 
of contributing to the main purpose of the enquiry. 
In this opinion I fully concur. I may add, however, 
that though Mr. Ward may be no longer in Ceylon 
next year, we may perhaps have yet the benefit of 
some researches on the nutrition of plant-cells, com- 
menced here in connection with coffee, but requiring 
for their completion work in the well- equipped labor- 
atories of Europe and facility of reference to living 
authorities and published memoirs. This work, though 
not strictly any part of the leaf-disease enquiry, bids 
fair to be of special value to the growers of our 
staple product. — I am, &c, Henry Trimen, 
Director, Royal Botanic Gardens. 
FROM MR. MARSHALL WARD'S REPORT. 
From H. Marshall Ward, Esq., to the Hon. the 
Colonial Secretary. 
Sir, — I have the honour to present you with a 
further report on the progress of the investigation 
into the life-history of Hemileia vastatrix, which I have 
conducted during my stay in Ceylon. 
You will see that the nature of the fungus, and 
its causal relations with " leaf-disease" on the coffee 
in the island are satisfactorily determined, and that 
the knowledge now to hand, together with what has 
been put forward in my previous reports, leaves no 
doubts as to the bearing of the several points established 
upon the general questions which have been raised. 
So far as coffee is concerned, the life history and 
anatomy of Hemileia tastatrix may be considered com- 
plete. The importaut periods occupied by Ihe several 
phases of its life history have also been ascertained, 
and a considerable number of developmental periods 
on the part of the coffee have been resolved and brought 
into correlation therewith. 
I have, moreover, to call your attention to the 
real connection between climate and leaf disease, which 
is no longer to be looked upon as a vague expres- 
sion ; but which I have shown to be of exactly the 
same nature as the relations existing between any 
other organism and its physical environment, and com- 
parable to the equally important dependence of 
coffee or any other plant upon climatic conditions. 
I have attempted to place the essential details of 
the history of this fungus, and its true relations to 
the coffee, &c, in the clearest form ; and have omitted 
no fact which throws light on the difficulties ex- 
perienced in understanding so intricate a subject. 
Having shown that the individual fungus plant is 
derived from without, and injures ti e coffee by 
robbing it of food — on the manufacture of which a 
large expenditure of energy had been employed— by 
occupying valuable space on the leaves, and by pro- 
ducing profound disturbances in the functions "of the 
plant, I further proceed to the examination of the 
obvious consequences of such damage on a large scale 
— the falling of leaves, blossom, and crop. 
The distribution of the fungus has also occupied 
much of my attention, and the fact that it is con- 
veyed from place to place by wind is now established 
by irrefutable evidence. Other important means of 
distribution are fully examined below, and the facts 
collected remove all difficulties in understanding the 
wide and rapid spread of the parasite by the quickly 
germinating spores. I further proceed to show what 
occurs on large masses of coffee, as cultivated over 
vast open areas in Ceylon ; and you will notice that 
the application of the preceding knowledge to the more 
complex problems there presented enables one to explain 
facts, or rather collections of facts, at first apparently 
difficult of explanation. One important point I would 
especially direct your attention towards : what is 
known to the planters as an attack of leaf-disease, 
followed by the fall of leaf, is not a simple matter, 
but the combined or successive effects of several gen- 
erations of the fungus. 
Much of my time has been devoted to experimental 
research into the efficacy of certain substances in 
destroying the fungus, and the advantages and disad- 
vantages possessed by such of these as can be em- 
ployed will be indicated below. It will be seen, how- 
ever, that the problem of combating this disease is 
not a mere matter of quantity of chemicals and their 
efficacy in killing the fungus ; in any scheme for miti- 
gating the ravages of the pest, provision must be 
made for removing sources of re-infection, and at the 
same time keeping up the strength of the coffee tree. 
Moreover, whatever the application to the diseased 
leaves, it is clear that its continued action can only 
be counted upon for a short time after each renewal. 
I have pointed out the importance of manuring and 
pruning, from the point of view suggested by the 
above, and it seems necessary to call particular atten- 
tion to the value of whatever break-winds, or tracts 
of forest, or patana, &c, may separate estates from 
