424 
THE TROPICAL AGRICULTURIST [December i, 1889. 
by the deep-feeding roots of the i atural herbage and 
by the still deeper feeding roots of the coconut tree 
itself. It must not be forgotten that on low-lyiug hats, 
Where an excess of moisture is ever present, draiuage 
both to raise the level of the land and to get rid of 
superfluous moisture is resorted to, even by the un- 
educated villager, whose only knowledge of the benefits 
of drainage is intuitive. The reference to the necess- 
ity of the pores of the soil being free to be occupied 
by air makes it clear th it my friend has in his mind a 
soil whose pores are occupied by wat^r. The pores of 
ordinary coconut soils in inlands districts are not so 
occupied, and as nature is said to abhor a vacuum, I 
think it tollows that the pores of such soils are occupied 
by air. 
I bel'eve I mentioued in my review that my system 
of draiuage was to cut shallow '-ontour drains traced as 
nearly level as possible, and throw tbe soil on their lower 
side so as to increase their capacity. I cut my drains 
from 9 to 12 inches deep, and 6 feet wide. The object 
with which I drain is primarily to catch as much as 
possible of the rain-water that falls on the laud, to pass 
it through the soil, and also by imposing frequent 
barriers across the face of a slope to reduce the volume 
and thevelocity of the water thai will otherwi-e rush 
along the surface. Tue benefits I expect to follow these 
operations are, 1, the aeration of a large surface of the 
soil by wide drains ; 2, the abstraction by the soil of all 
that is of manurial value it) rain water ; 3, the storage 
in the soil of large quantities of wa*er that can be 
drawn upon for use in seasons of drought ; 4, the pass- 
age through the soil of air in the wake of the water ; 
and 5, the absorption of the water that falls on the 
surface where it falls by the imposition of frequent 
barriers. 1 should be glad of au authoritative opinion 
as to whether this system is faulty, and whether too 
much is expected from it. 
My friend writes further, " Tbe deeper the roots are 
induced to sink, you will admit that the better the tree 
is insured against lack of moisture. How could this be 
done better than by deep cultivation and drainage." 
Plants have generally two kinds of roots, laterals and 
the tap root. The latter makes its appearance with 
the bursting of the germ and has a downward tendency. 
The duty of the tap-root is to anchor the plant firmly 
on the ground. I wish to be informed what the oth;r 
functious of the tap-root are. I remember having 
read somewhere long ago that, in addition to the duty 
it performs as an anchor, it acts as a pump to the tree, 
and most of the water a tree is supplied with is through 
the tap-root. Its powers of suction are said to be so 
great, that in sandy regions trees have been cut down 
with a hard and almost solid column of sand in their 
heart and seemingly incorporated with the wood.- As 
the trees had no external injury through which the 
sand could have found its way inside, and even if in- 
juries did exist it not being possible that the saud could 
have been found in the state it was argued tbat it 
must have been forced up with the water through the 
tap-root. The coconut tree, in commou with all palms 
I believe, has no tap-root, but it has roots correspo.id- 
ing to it and which from their earliest period of life 
have a downward tendency. In digging a well in a 
piece of low-ground not very long ago, I came across 
these roots 7 and 8 feet below the surface and at water 
level. I was told by an old and experienced planter 
that in Jaffna, when digging a tank he came across 
coconut roots fully 20 ft. below the surface. These 
roots have a wonderful power of working their way 
down even in very hard soil. The laterals on the con- 
trary are invariably found at the surface, and seldom 
go beyond the depth of the surface soil. In a shallow 
soil the lateral roots of the Coconut tree will all be 
found at the surface. The reason for this is obvious. 
From tbe laterals spring the root hairs or feeding roots, 
and these instinctively abound where most food is 
available. What I wish to know is what roots it is 
intended to drive deeper in'o the soil by deep drain- 
age ? If the roots tbat correspond to the tap root, I 
think it will be found that in a Coconut Estate these 
will have already found their way, except on a very 
young plantation, beyond the influence of even deep 
drains. If the lateral roots will by simply increasing the 
poro-ity of a soil induce roots to have their feeding 
grounds and seek others wLeie food is not immediately 
available, for it cannot be pretended that insoluble 
particles of soil become soluble simultaneously with 
their coir act with air? The process is slow, and the 
time it occupies depends on the degree of insolubility 
of the soil if I mistake not. 
Against deep tillige I have nothing to say; but of 
the wisdom of deep draining on land that does not 
suffer from a superfluity of moisture, and for a product 
tbat suffers more from want rather than from excess of 
moisture, as at present advised I am not convinced, 
The point at issue between my friend and myself is. 
whether a shallow or deep drained soil has more avail- 
able moisture. It must not be thought that the position 
I have assumed is that of a critic. I am an earnest 
seeker after knowledge ; but my frame of mind is 
such that I cannot accept anything as a truth till I 
h >ve fully satisfied myself that it is such. — B. — Local 
" Examiner." 
Ceylon Oolongs.— Did you see the fine prices 
I got (or rather my brokers H. A. Hertz & Co.) 
for a small shipment of oolongs the other day ? — 
bro. pek. Is 4Jd, pek. Is 5d, pek. sou. 10jd. Who 
says Ceylon can't make oolongs after this. — Cor. 
Tea. — On dit that the Dublin branches of the 
London and Newcastle Tea Company are arranging 
to open drug and patent medicine departments in 
connection with their stores, and with a view 
of pushing the sale of their Bohea purpose to " cut" 
the ohemists at cost price.— Chemist and Druggist, 
Oct. 26th. 
Thoughts Suggested by Akticle on Coconut Dis- 
ease. " Why is it i tbe disease) worse this year than it 
bad ever been before." This question has never been 
answered with regard to other plant " diseases." It is 
almost impossible of answer. Wheat rust, Coffee leaf 
disease, Phylloxera, Potato disease &c. are all new dis- 
eases. Tne words '"new diseases" are ominous. The Pota- 
to disease was unknown till about 1846. The vine diseases 
are equUly modern. Coffee planting in Ceylon was 
ruined since 1872. Are we developing uew diseases ? It 
looks like it — Science Gossip, Dr. Taylor. Betore we 
call in the aid of a Scientist from England, I think it 
best to find out with local talent if the paiasitic fungi 
existing on the leaves of other trees are identical with 
that on Coconut leaves. Specimens of all leaves affected 
can also be sent to England by Government to settle this 
point. If Government supply me with small bottles 
aud spirits, 1 can forward samples to be sent to Kew. 
Dr. i'rimen detected a fungus and not the fungus on 
decayed leaves. This can be detected by any layman 
with the naked eye. This fungus is probably one of 
tbose bred by decayed vegetable matter. The bug has 
not been discovered, i. e. the bug Dr. Trimen imagined 
made tbe punctures that produced discolouration, but 
a bug that has nothing to do with the diseased con- 
dition of the tree. The lungus that is the cause of the 
disease has been discovered by Mr. Potier. Mr. Potter 
does not recommend tbe application of fire to growing 
leaves. Its effect will be to destroy their vitality. "If 
all affected leaves could be burnt" surely does not mean 
the aplication of fire to growing leaves. The same re- 
medy was suggested for Coffee leaf disease, and the 
suggestion was not taken to mean the application of fire 
to growing leaves. Is burning possible without destruc- 
tion ? With regard to the Kerosiue emulsion cure you 
suggest, Marshall Ward says with regard to a cure for 
leaf disease : " It must effectually kill the germinal 
tubes before they enter the leaf and yet must not in- 
jure the Coffee. The cure must be capable of rapid 
aud wide diffusion so as to reach every germ. It must 
be very soluble, so that it may be taken up by the water 
in which the germ tubes are forming. It must act for 
a long time aud continuously, in order that the later 
germ tubes may be attacked as they form." The re- 
medy must be applied during wet weather, as it is then 
that reproduction takes place, and it must be con- 
tinuous. The " sprayer " might be efficacious. — Cor. 
— Local '• Examiner," 
