2S8 
THE TROPICAL AGRICULTURIST. 
fOcT. 2, 
stored up all the Winter until set in motion by 
the genial influenoea of Spring." 
With reference to this " Young Planter " writes 
as foUowB : — " To say that the gap elaborated by 
the loaves is stored up in the bark, might have 
received credence in a by-gone age, before experi- 
ment demostrated that it deeoeoded to ibe roote 
between the cambium layer of the wood and the 
inner tissue of the bark." 
Novf if your Indian correspondent made a slight 
slip in using the word " bark," when he might 
in a general way have said " stem," his Ceylon 
eritic has certainly been very hasty in ibe making 
the statement be has done. To begin wiih he 
baa misunderstood what Mr. McEeDzie (the writer 
fiom the Nilgiris) intended to convoy, for Mr. 
MoEenzie in the passage from his letter quoted 
above, did not intend to describe the behaviour 
of tho sap in dicotyledons duriog the ordinary 
periods of growth, but its behaviour in deciduous 
trees during Autumn and Winter vihen growth is 
Arrested. If Mr. McKenzie was wrong in 
sajing that the descending or elaborated sap (tor 
that is the eap meant) was stored in the bark, 
" Young Planter " is quite a? wrong in s&yiog that 
it "descended to the roots," In concluding his letttr 
" Young Planter " writes thus : — " But if your cor- 
respondent will refer to any standard work' on 
Botany, I doubt not that he will modify hie vievts." 
Now, aa I ahall probably be credited with little 
authority it I gave an opinion, aa my own, 
on the queetion at issue, I have decided to 
follow the advice ofiered by " Yuung Planter " and 
not only refer to standard works on Agriculture and 
Botany, with which my library ia fortunately well 
furniehed, but also to quote from them, and tbua 
settle the matter. Warrington in his " Chemiatry 
of the Farm," writing on plant development, 
eajB, "In trees plaint food ia stored up at the 
end of summer in the pith, the pith raya, and in 
the layer between the wood and bark, The leaves 
which fall in autumn have lost nearly all their 
starch, albuminoda, phoaphoric acid and potaeb, 
these having been transferred to the stem. By 
the action of the sun in spring-time the new buds 
swell, the sap rises, the starch and other matters 
deposited in the wood during the previous autumn 
are re-dissolved, and employed for the production 
of new growtha." Thia very clearly indicatea that 
the aap in autumn and winter ia in the caae of 
deoiduoua perennial dicotyledons, atored up in the 
tissues immediately in contact with the wood and 
surrounded by it, viz., the pith, the cambium, and 
the medullary rays. So that, as I said before, if 
Mr, McEenzie erred slightly in saying that the 
sap was stored in the bark, which lies outside 
the cambium layer, '■ Young Planter " waa very 
far out in insisting, at least in the caee of the 
trees referred to, that the aap goes down to the 
roots. In the oape of biennials it is true, to quote 
Warrington again, that " towards the end of 
snmmer there is a storing up of concentrated plant 
food in the root or stem to serve for the com- 
' menoement of growth in the following spring. In 
a biennial root crop, the turnip, for instance, the 
root attains a great size in antumn, the eaves 
dying after tranaferring to the roots their most 
important oonstituents. The next reason the root 
throws up a flower stem, and the store of matter 
Booumulated during the previous autumn is con- 
sumed in the production of seed," In the potato 
the store house is the stem and not the root. 
But Mr. McEenzie was referring to the deciduous 
trees of England (and by analogy to the tea plant) j 
not to bienniala, And even referring to ordinary 
oirouniBtauoea of growth it is incorrect to say 
tbftt tbe oUbocated sap deioendi ''to the rooti" 
^s " Young Planter" puts it. The fact ia that " the 
latorateJ aap forma downward and oroea currents 
varyiDg in direction and intenaity aooording to the 
requir*.mentB of the growiug tiemea and tbeir 
coDlormation." It ia difficult to uoderetand what 
puipoee could be aetved in the plant b«onomy 
Ly the sap coUocticg iteelf in the roots alone. 
I am here reminded of Dr. Maeter'a warning in 
Li3 work on " Plant life" :— *' It is neoeeEary," he 
eaya, "to guard againbt the etili prtvalenl iiillaoy 
attaching to the use of the word ' eap.' That term 
was fifot employed when it was imagiued that a 
regular circulation o( fluid took place in plants 
from tool to leaf atd Irom leaf tack to root — 
just aa in animals It^e blood couraea from the 
heart to the capilaries, and back from the capi 
laries to the hiart by the vi ing." This ia a warniug 
which I cacioot help tbiuking id applicable to 
" Youi g Planter's" case. These are the only pointa 
beariug on the " theory" of Mr. McEenzie. " Young 
Planter ' gives further information on the medium 
through which the ascending and dcsceoding taps flow, 
but is obacure when hu says ihut ttie latter descends 
" between the cambium layer of the wood and the 
inner tissues of the bark." Still further, be etates 
that in spring ''water is stored in the stem, — not 
the bark, mark you !— to meet the immidiate 
demand of expanding buds and cell .ite gemraily," 
but no reference was made to apring aiorint;, but 
only to storing during winter when there ib ceaaation 
of growth analogous to that proauced by tea piun- 
ing. Lhstly the causes of thu upward flow ol itie 
crude sap (a subject which Mr. McKeozie did not 
wish to burden your columos w.th a ditrserlaiun on, 
as having no direct bearing on the quettion at 
present at iaeue) la taken up. 
Mr, McEenzie' communication in my think- 
ing is a most interesting production and 
he works out the analogy between the win- 
tering tree and the pruned tea bush with 
much ability, at least frum a scicntifio point of 
View. I shall watch the treatment oi the aubjeot 
from a practical standpoint with much interiat. 
The IctEt paragraph of Mr. McEenzie'e letter is, 
however, an unfortunate production. I ehoaid 
hardly have expicteci him to be aetonidhed or 
rather amused to find it said by your London cor- 
respondent that tea can appropriate nourishmenl" 
(the italics mine) in spite ol the fact thial nitrifi- 
cation is only po^slble in the topmost twelve or 
(as afterwards corrected into) eighteen inches or 
two feet of soil, according to texture and composi- 
tion.— Yours truly, AGttlCULIURlbX. 
HELOFELTIS AT HItiH AND LOW 
ELEVATIO.NS. 
De&b Sib, — I was first introduced to Helopallii 
Bome 7 years ago at en elevation of 6,000 feet. 
I was sceptical as to its identity until the micros 
cope and Uol. Money were brought to bear on it 
when I had reluctantly to ooofess Us existence. 
It did but little harm however, and I am glad to 
say 1 have not seen the slightest evidence ot it for 
years, so I think there need be lo fear of its becom- 
ing troublesome at the higher elevations. 
1 doubt its general prevalenoy in the low oountry 
as I havs not yet seen any appearance nt its presence 
on an estate 20 miles east of Colombo. J, F, 
Coffee in Brazil. — The bureau of Ame- 
rican republics is informed that tfie Committee of 
coffee factors of Brazil, appointed to estimate the 
coffee crop available for exportation from that 
market, ratifies the estimate already published of 
2,700,000 bags as the maximuai export from Brazil 
I for 1893, This is a large decline from previoaa otope. 
