June i, t598.] TH^ TR0I‘ICAL AGRICULTURIST. 851 
show how futile were fill the attenfipte<l 
iiiedies, and how absurd were some of the 
theories as to disease in the soil, in 
the roots or in the sap of the bushes. 
But in regard to Cacao, Mr. Carruthers seems 
to have a more complex jiioblem inasmuch 
as he has two enemies or two forms of 
attack to deal witli, the fungus inducing canker 
in the system of the tree and the fungus or 
canker at*^acking the pods. On bis arrival in 
the island without that amount of previous 
preparation in reading up the literature on 
Cacao plant diseases, or on tliis particular disease 
which might have helped him,— Mr. Carruthers 
found himself all at once in a paradise tor 
fungi. The estate in which his work lay 
shewed the disease on trees of all ages, and 
apparently in all situation.s. On the richest, as 
well as on poorer, soils ; in sheltered as well 
as exposed situations and in different 
aspects. This was not an encouraging stale of 
things for the investigator ; but as -a fungologist 
he no doubt was. satislied with the abundance of 
specimens of the fungi which would be avail- 
able to him. He first of all demonstrated that 
thedisease was not in the roots or leaves ; but when 
he came to the fruit, the case was very different 
and the large percentage of pods lost through its 
operation indicates how important is the investi- 
gation entrusted to Mr. Carruthers. He shews 
how readily damage due to drought or 
helopeltis can be distinguished in the pods 
from that which arises froni the fungus 
and then we have a description, more or 
less technical of the experiments niadc, and a 
careful description of the external signs (from the 
earliest appearance) of the canker. 
Finally, we have a very valuable summary ot 
the problems Mr. Carruthers recognises as still 
awaiting solution, and for which he is preparing to 
carry on his further inve.stigation. It is too soon to 
talk of possible preventives or cures as anyone 
may see from noting the stage arrived^ at. But 
W6 fc6l thfit Mr. Cfti'iufcUcrs is on the riglit ti;ick 
to arrive at useful results as regards preventives 
if not remedies, and that he should have a 
unanimous vote of confidence at this stage and 
be encouraged to go on as deliberately and 
thorou»bly as he has begun. It may be said that 
one of” tlic two suggested forms of amelioration 
the diminution of “shade,’ — would mean 
goiiio from the frying-pan into the hre, as 
likely to induce helopeltis. Mr. Carruthers ve- 
cognues this possibility and nothing but prac- 
tical experiment can show in what the sate or 
happy medium consists. Far less doubt oe 
felt about the propriety of burriing aff^ected 
branches or pods as soon as the disease is ob- 
served. Finally we trust all cacao planters will 
carefully study Mr. Carrutliers’ instiuctions, so 
as if possible, to carry on observ.ations and ex- 
periments for themselves with such notes as may 
move useful in connection with the mam in- 
vestio-ation. We consider that Mr. Carruthers 
has Already fully justified his appointment to 
this investigation and we sinceiely trust the 
future course of his work will still furthei de- 
monstrate the value of his services to the 
Cacao Planters ot Ceylon. 
COFFEK IN Mexico. -A very unfavourable re- 
port about Mexican investments will be 
found elsewhere ; but with “ good coilee 
selling in London at 28s per cwt., the prospect 
everywhere seems Poor ? 
CACAO DISEASE INVESTIGATIONS. 
INTERIM REPORT BY J. B. CARRLJ- 
TIIERS. 
In this report I propose to confine' myself almost 
entirely to a statement of observed facts as far as 
they seem at present to lead to a knowledge of the 
cacao disease ; but many facts observed are unre- 
corded here, and may at a future time be of use 
when a final and fuller report on the investigation 
is submitted. 
Leavii g England at short notice I had no time 
to make myself acquainted with any literature which 
might bear directly on these diseases of cacao if 
any such exists, and, therefore, on arriving here 
began ah initio in my researches into the cause 
of the deterioration and death of the diseased trees. 
The Director of the Royal Botanic Gardens very 
kindly placed at my disposal the result of his observa- 
tions on the disease, as well as all the information he 
had accumulated from planters and other sources, and 
the two most valuable circulars issued by him showed 
me the knowledge of the disease possessed by planters 
up to that time. 
At the estate where I began my work I was fortun- 
ately able to see diseased trees of all ages, both of 
Forestero and Red Cacao, and had every facility 
given me for experimenting on Ihese and on healthy 
trees. 
The fact that trees of all ages, from three or four 
years upwards, in the best and richest soil and in 
favourable aspects, were attacked, and that trees ap- 
parently in a most healthy condition became victims to 
this disease, pointed to its being the result of extraneous 
parasitic organism — either plant or animal — no animal 
injuries could be foijpd exclusively on diseased trees, 
and therefore the supposition that it might be due to 
a fungus was a fair one, and I at once proceeded 
to learn if this was the case by discovering the fungus 
and endeavouring to induce it in a previously healthy 
tree. 
The conditions favourable for the growth of fungi 
are moisture and heat ; the latter of these is always 
sufficient in this country, but the former is more 
occasional. At the time cf my arrival the North-East 
monsoon was providing a time most advantagous to 
fungi, and I spent the first week in collecting and ex- 
amining all the fungi I found upon the cacao tree. 
Here I may say that one of the difficulties in an 
investigation of this sort is the very large number 
of fungi to be found in the cacao like all other 
plants, which are either saproph3'tic, i.e., living on 
dead trees or dead portions of a. tree, or merely 
superficial, like the Lichens. Both these classes 
are of little interest in this investigation, as the 
former, though often occu; ring with tlie disease, are 
an after-effect, appearing whe.i the damage is done ; 
and the latter have, as a rule, no effect whatever 
on the health of the tree. But the difficulty lies 
in distinguishing between these and the parasitic 
fungus which is the real cause. 
In order to discover the nature of a fungus and 
to learn its life history, it is necessary to observe 
its reproductive organs, just as in identifying flower- 
ing plants the flower must be found. Two methods 
can be followed in such a research, either to dis- 
cover the fruit of the fungus in the field (and this 
is naturally a not very easy matter, owing to the 
small size of the reproductive organs of fungi), or 
to place some of the mycelium or roots of the fun- 
gus under conditions most favourable to their re- 
producing themselves, and keep them under close 
observation. 
The difficulty in this latter method, especially in 
this country, is the large quantity ol B.acteria, Torulae 
and other organisms which it is almost impossible to 
exclude from the cultures, and which destroy the fungus 
under observation. 
In the case of the cacao disease it was necessary in 
the first place to form some conclusion as to portions 
of the tree affected. The examinatioH of the roots 
of badly diseased trees showed no sign of fungus, and 
