5 * 
THE TROPICAL AGRICULTURIST. 
[JULV I, 1890. 
taken up by both our couuty agricultural societie 
and the Royal Agricultural Society. — I am, sir, you 
obedient servant, W- G. Winearls, 
Swaffham, Norfolk, 4th March, 1890. 
THE MICROSCOPIC STRUCTURE OF PLANTS, 
AND ITS RELATION TO CULTIVATION. 
A very interesting discussion took place at the Paris 
Botanical Congress last August, and a report of which 
is now before us, on the employment of microscopical 
characters as an adjunct to classification. M. Vesque, 
who introduced the subject, was, we believe, perfectly 
right in insisting that the comparative study of the 
microscopical characters presented by plants should 
receive a due propoition of attention as other 
characters do. It does not follow that they are better 
or worse than others. We do nob know at pre.sent 
what their precise value may be, whether they are 
as subject to variation as others ; but their impor- 
tance ca nnot be denied, and to allege that they are 
difficult and troublesome to investigate, though it 
may be true, is no argument against their intrinsic 
value, In so far as they are hereditary, and, there- 
fore, relatively constant, they are known already to 
be valuable aids in discriminating the larger groups 
of plants, and what M. Vesque and some other 
naturalists are anxious to do, is to extend the use 
of these characteristics to each natural family of plants, 
BO far as circumstances permit. Any arrangement 
founded on these characters alone, would, of course, 
be just as unsatisfactory as any other artificial or 
incomplete system would be. We do not suppose that 
M. Vesque has any intention of founding a system 
entirely on these characteristics. For classificatory 
purposes the congenital characters, more or less fixed 
by long hereditary transmission, are naturally prefer- 
able to those characters which are called “ adaptive,” 
because they vary according to ciroumstancts. These 
are the characteristics, the possession of which enables 
a plant to sustain itself under new or adverse conditions ; 
these are the endowments in the absence of which the 
plant cannot survive in the battle of life. Whether 
then, from the point of view of classification, of re- 
lative constancy, or from that of adaptation to varying 
conditions, the anatomical characters appear to be of 
the highest importance, and this is so obvious that 
it seems strange that any contrary opinion can be 
maintained. Such an opinion can only be entertained 
under a misapprehension. 
But in these pages we are more directly concerned 
in the relation these characteristics bear to the cul- 
tural art. It is certain that many structural details 
are directly associated with variations in the conditions 
of life. The structure of a plant that passes its life 
in water is widely different from that of its near re- 
lative that grows on dry land. So intimate is the 
relation between the structure of a plant and the 
circumstances under which a plant grows naturally, 
that it is very often possible to recognise in a pre- 
viously unknown plant the kind of liie it must have 
been subjected to. Of course from our ignorance and 
limited knowledge, there are many exceptions and 
much that seems anomalous. But these facts form 
no valid argument for not availing ourselves as far as 
we can of what we do know, still less does it consti- 
tute a reason for not pushing our researches further 
in this direction. M. Max Oornu, in discussing M. 
Vesque’s paper, seems to have objected to it as pro- 
posing a new system — a substitute for the natural 
system — but a perusal of M. Vesque’s writings leads 
to no such conclusion. All that M. Vesque wishes to 
do, so far as we can make out, is to enlist anatomy 
in the work of perfectionatiug the so-called natural 
sj stem. 
M. Uornu, too, also raises objections to the employ- 
ment of anatomical chaructcrs as a guide to cultivators. 
M. Vesque said that the anatomical structure [some- 
times] clearly indicates the natural of the physical 
conditions to which the plant is adapted, and which 
must be realised as much as possible under cultiva- 
tion. To this M. Max Cornu objects, and saye that 
we cannot in general realise what conditions would 
be necessary in the case of plants removed from their 
natural surroundings and placed under other circum- 
stances, to which they must adapt themselves or perish. 
Many of them live and prosper under the new con- 
ditions — conditions which are quite different from the 
natural ones. What information, asks M. Cornu, could 
the study of structure give us, since different con- 
ditions give results superior to the normal ones? 
Coffee, says he, requires a rich (forte) toil in the 
tropics ; it would perish here if grown iu such a soil. 
The Nepenthes cannot, he says, be grown here except 
in an extremely porous substratum, while in Sumatra 
the soil in which the Nepenthes grows is a heavy 
impermeable loam. 
In repljing to M. Cornu’s observationi, M. Vesque 
admitted his inability to reply to the two special cases 
— that of the Coffee and that of the Nepenthes, but 
stated that he was chiefly concerned with the relations 
of the structure to light and moisture, and doubted 
whether M. Cornu would succeed iu making a plant 
adapted to grow in the shade flourish in full sun, 
and vice venS.-, nor a plant adapted to a dry climats 
thrive in a moist one. In support of his argument, 
M. Vesque called attention to the construction of 
plant-houses divided iuto separate compartments, 
allowing of variations of temperature and moisture. 
Anatomy often indicates what the treatment ought to 
be, or, inversely, in which corapartmeu t( cal) we 
ought to p'aoe a plant. 
Great difficulties stand iu the way, no doubt ; the 
application of a knowledge of anatomical structure 
to cultural purposes is in its merest infancy, but that 
it is destined in future to play an important part in 
practical horticulture, seems to us as absolutely certain 
as that a knowledge of the letters of the alphabet 
will, under given conditions, enable a gardener to read 
the Gardeners’ Chronicle! It is not to be expected 
that practical gardeners can as a rule become expert 
microscopists, but they can profit by the skill of others, 
and it is the duty of those who have the power and 
the means at their disposal to hasten and foster the 
progress to the utmost of their ability. — Gardeners’ 
Chronicle. 
♦ 
INDIARUBBER. 
In these days, when local horticultural societies are 
formed in almost every provincial town, and when 
botanical and horticultural novelties attract so much 
attention from scientists on the one hand and cul- 
tivators on the other, the practical value of the com- 
bined efforts of both seem likely to be lost sight of. 
The interest attached to the successful growth, or to 
the flowering of a rare plant like the Amorphophallus 
at Kew last year, is equally divided between the 
scientific botanist and the practical horticulturist, but 
the introduction and successful cultivation of some 
valuable economic plant in countries very far distant 
from its native home, does not secure half so much 
popular attention, though the benefits accruing from 
it to the world at large are infinitely greater and of 
a more lasting character. What is the production of a 
double flower where a single one was known before 
only to exist, or even the introduction to our stoves 
of such plants as the Victoria regia and the Amorpho- 
phallus titanum, or, if possible, the Rafflesia, and 
Welwitchia, to the etablishment in India of the Cin- 
chona plants which has been the means of bringing 
that most important medicine, quinine, within the 
reach of all. 
The result of this successful enterprise will always 
stand as a monument of the union of science with 
practice, and one of the benefits to the world in which 
Kew has played so large a part. 
Next to this achievement, the introduction of rubber- 
producing plants into the various possessions of the 
British Empire is undoubtedly of the greatest impor- 
tance. Though the whole history of these experiments 
has been given in the Reports of the Royal Gardens 
Kew, ranging between the years 1878 and 1882, it may 
be of some interest to point out that whereas some 
