476 
THE TROPICAL AGRICULTURIST. [January i, 1889. 
To the Editor. 
THE COCONUT PALM DISEASE IN THE 
WEST INDIES. 
Botanical Department, Trinidad, Oct. 26th, 1888. 
Dear Sir, — I note that in the August number 
of your valuable monthly you quote, from the 
Bulletin of the Jamaica Botanical Department, 
Mr. Pawcett's notes on the coconut disease, but the 
mention of my nam6 as having reported on the 
matter in Sept. 1886 is somewhat misleading, 
as the enclosed copy will show. Mr. Morris and 
myself issued reports on the matter concurrently 
and without the knowledge of eaoh other ; but, as 
my report was only published in the official organ 
(Government Gazette), it did not obtain the 
publioity that his did, and was aotually unknown 
both to himself and Mr. Fawcett until I called their 
attention to it after the publication of the article 
which you republish. 
Mr. Morris' report is coincidentally confirmed by 
my own, and the similarity of the conclusions 
are somewhat remarkable, the only difference of 
importance (if any) being in the application of a 
suggested remedy, and the primary cause of the 
disease. 
It is admitted by Mr. Morris, Mr. Fawcett, and 
myselt that the scale insect is the ultimate cause 
of death, but I do not think they insist so strongly 
as I do upon the importance of combating the 
predisposing cause. Personally I place much 
reliance upon remedying the primary and pre- 
disposing cause when endeavouring to counteract 
the dire effects of the disease, while my respected 
co-workers appear to lay much stress upon the 
urgency of removing the insect pest. 
This, of course, corresponds to the usual difference 
of opinion which is well-known to exist with regard 
to the many diseases to which vegetable and human 
life are unfortunately subject ; on which arises 
the question, whether is it better to find and 
remedy the predisposing cause, or to stamp out 
the ultimate cause of death, leaving the predisposing 
one rampant for all ill ? 
That the former is the more successful policy 
to pursue would appear to be evident, for when this 
is done the ultimate or secondary cause generally 
disappears, after having attained a certain mortality, 
without the use of any hard course of opposition. 
In confirmation of this view I am supported by 
the opinion, observations and experiments of Pro- 
fessor Harrison of Barbados, who has devoted much 
attention to the subject since the issue of Mr. 
Morris' noteB on the Barbados trees. For on carrying 
out the treatment suggested in the 16th para of 
my report he has been entirely successful where 
it has been deemed a " hopeless task" to grow 
them while the " disease is present." 
Traced to its primary source, it would appear 
to be fairly apparent that the so-called disease 
is in the majority of instances caused by a state 
of semi-starvation, induoed either by drought, or 
by a deficiency of manurial constituents in the soil 
of the particular district, and that, when these 
causes do not obtain, it disappears ; unless it has 
become through a continuity of incidents severely 
epidenrc, when the distribution of the insect pest 
by winds or other causes would, by the immensity 
of their numbers, cause healthy and well-nourished 
trees to eventually succumb. 
Although healthy growth, favorablo seasons, and 
a sufficiency of food would probably bo in the 
majority of instances col... ident where the balance 
of nature is not disturbed, there yet remains the 
fact, that the assemblage of large numbers of one 
particular species of plants or animals (man in- 
cluded) is conducive to destructive ageDts in various 
forms, which would otherwise or under other con- 
ditions be perfectly harmless, and that when a 
destructive organism or one that has become de- 
structive reaohes such a practically unlimited field, 
where the natural balance of nature is unduly des- 
troyed by the hand of man, it will, and does, work 
its way, in spite of all the skill that practical 
experience and scientific effort can suggest, as you 
must .know to your cost in Ceylon with regard to 
coffee leaf disease, which will probably never be 
eradicated until the predisposing causes (be they 
what they may) are removed or disappear. 
Plant diseases appear to require the same me- 
thod of treatment as those affecting man. Our 
physicians of the present day would not rest satis- 
fied with merely eradicating or staying the ravages 
of any special disease in the single human body- 
Where is the doctor of modern education who would 
be satisfied with stating that 'such and such' a 
disease was the cause of death without trying 
to fully understand how the disease was caused, 
its history and progress, and though he might 
write Phthisis pulmonalis would not understand 
and treat that disease according to the modern 
knowledge of its predisposing causes, and would he 
not also know, how almost worse than useless, 
were anything but palliative measures in the latter 
stages of that disease? 
Are not the sanitary scientists of the present 
day doing more for mankind than all the old con- 
servative drug doctors of former generations, and 
why ? Because they have searched for and found 
the predisposing cause of many diseases, and have 
thus been able to draw up accurate methods of 
treatment which have enabled them to combat them 
successfully. 
In addition to what is given in my report, I 
would now add that I am much in favour of 
mixed planting, i.e., that although each crop should 
for economy's sake be planted together, still that 
it should be done in smaller areas than is now 
usual, and that alternate areas of other crops 
should be the rule so as to disturb Nature's balance 
as little as possible, especially where the situation 
is at all unfavourable. 
My report was founded upon returns received in 
answer to a circular issued under the authority of 
the Jamaica Government to some of the largest 
cultivators in that island, and it has therefore more 
authority than if issued as the re=ult of my own 
individual experience. 
J. H. HART, f. l, s., 
Superintendent, Botanical Department, 
Trinidad. 
(Extract from "Jamaica Gazette.") 
No. 210. 28th June 1886. 
The Governor directs the publication for general 
information, of the following copy of a paper prepared 
by Mr. J. H- Hart, Superintendent of the Government 
Cinchona Plantation, embodying results of inquiries 
made on the subject of the disease effecting the coco- 
nut paim. 
REPORT ON COCONUT DISEASE. 
The importance of an inquiry being made into the 
disease affecting coconut trees in Jamaica having been 
proved by continued applications to the Botanical 
Department requesting the suggestion of remedial 
measures led to the issue of a circular containing 
questions, which, it was thought, would tend to eluci- 
date some useful information concerning the nature 
and extent of the "disease," notes were also made 
on it by D. Morris, Esq., late Director of the Depart- 
ment, during visits to some of the districts, and notus 
have also been made in districts by myself. 
