572 
THE GARDENING WORLD 
May 7, 1898, 
Of course this does not apply to the open ground 
where the surface of the soil can be constantly 
stirred and other air spaces renewed ; neither do I 
refer to the mulching of plants in pots, where, if the 
material used is as it should be, there is no hindrance 
to either air or water. 
Well then, if you are going to give a plant manure 
that is to be easily assimilated or taken up by the 
plant, and where you do not want all the energies of 
the same to be spent on food conversion, but where 
you want all its energies thrown into growth, and the 
development of its floral organs, I believe in apply¬ 
ing it, whether it be artificial, farm-yard manure, 
organic or inorganic ingredients, in a really soluble 
state, not of much greater density than clean water. 
There is no doubt that the best plan is to soak all 
manures before putting them on a pot, and if a plant 
is to be forced, and is required to grow to perfection 
in a short space of time, it must be fed by solutions 
and by foods that are easily assimilated. Again I 
maintain that a knowledge of root function cannot 
fail to be a help to the gardener. 
Then there is another point which we must notice 
before leaving the root, and that is the process of 
exosmose or the outflow carried on by the root. 
From this also we can see the necessity in the rota¬ 
tion of crops, because, as you all know no two orders 
of plants contain the same chemical composition of 
sap. Therefore, it is plain that the sap of one order 
would convert certain mineral substances into plant 
food which the sap of another could not do. 
Now with the stem we shall be very brief, just 
noticing a few forms of stem. The stem receives 
various names according to its duration and 
structure. In herbaceous plants it is called caulis, that 
is stem, which dies down to the ground naturally 
every year, such as Asparagus, etc. Stem is termed 
culm in grasses, triincus in trees, caudex or stock in 
Palms and Cacti, and stipes in Ferns. 
Then we pass from the stem to another very im¬ 
portant part of the plant, and that is its leaves. 
Leaves as you know, carry on a very important 
part in connection with the growth of the plant. 
All the sap that is taken up by the roots is carried 
up to the leaves and there it undergoes various 
changes, through the agency of light, air, &c. 
The sap in its ascent passes up through the young 
wood and flows to the leaves, carrying with it the 
mineral ingredients of plant food. The leaves take 
up their carbon in the form of carbon dioxide from 
the atmosphere, and under the influence of sunlight 
the materials are rearranged chemically and built up 
into the substanc es which go to the increase of root, 
stem and leaf. A considerable amount of it is 
drafted into the cambium layer between the bark acd 
the young wood. In this region it goes to thicken 
the stem and part of it passes downwards to extend 
the root system. When rooting cuttings you will 
find that the young roots are produced from the 
cambium layer, the new material descending from 
above, not rising from below. 
When you ring a Dracaena or any other plant for 
the purpose of rooting it the roots would form from 
the under lip instead of the upper one if the buildiDg 
matter came from below, and not only this, but the 
upper part of the plant after being ringed would 
wither and die under the conditions named, because 
all communication from the root would be cut off. 
Now there is a practical point which presents 
itself, and it is this : Should a cutting be divested of 
its leaves before being put into the soil, or should it 
be put in with as many leaves as possible ? My 
opinion is that this depends almost entirely upon the 
place you have to root it in. If you put a cutting in 
an atmosphere that is almost at the point of satura¬ 
tion, no evaporation can take place from the leaves, 
then I prefer as many leaves as possible, because the 
more leaves you have on a cutting, where it cannot 
flag,the more do they assist in the formation of roots. 
If, on the other hand, you expose the cutting to a 
drying atmosphere then I would advise the stripping 
of its leaves almost entirely. If not, with an arid 
atmosphere these leaves will evaporate the life blood 
of the cuttings, and give it off to the air. 
Then again there is another point to be taken into 
consideration, and that is the power that some plants 
have over others in giving off moisture. Plants 
whose natural habitat is a high and dry atmosphere, 
have always a feeble power of evaporation ; whilst 
on the other hand those of warm and moist climates 
have a great power of evaporation. It is generally 
supposed that plants evaporate more by the agency 
of light than by sun heat. 
Now, how is this process of evaporation carried 
on ? It is carried on principally by breathing pores 
in the leaf, known as stomata, which mean mouths. 
They are openings placed on the epidermis of the 
leaf and consist usually of two crescent-like cells, 
supposed to resemble the lips and the orifice of the 
mouth They open and close according to the state 
of the moisture or dryness of the atmosphere. 
Then again the position of the leaf also affects 
stomata Leaves which are borne horizontally have 
much the largest number of stomata upon the 
under side. 
Then again, leaves which are borne vertically have 
often an equal number on each side. Take for 
instance the Hyacinth, where you will find them, 
with a very little magnifying power, irregularly 
distributed over the surface of the leaf. 
The number of stomata varies very considerably 
on different plants, from a few hundreds to many 
thousands on the surface of the leaf. 
Another point of importance as to how a know¬ 
ledge of botany may help a gardener is in defining 
the division or otherwise of the leaf, whether it be 
simple or compound, pinnatifid, or palmatifid ; and 
to define its margin, whether it be serrate or what 
This I think to be most important to a gardener, as 
the shape of the leaf is so often asked for when one 
has to describe a plant. The venation of the leaf is 
also very important in the classification of plants. 
You will always find that in the case of dicotyle¬ 
dons the venation of the leaf resembles network, and 
is said to be reticulated ; while in monocotyledons 
the veins are parallel from margin to midrib ; and in 
acotyledons the veins are forked, as in Ferns. 
(To be continued.) 
SPRING FLOWERS IN REGENT’S PARK. 
Regent’s Park has an individuality peculiarly its 
own, and this individuality lends itself with remark¬ 
able ease to the accommodation of spring flowers. 
It has no Serpentine, and no Row, but it manages to 
do very well without them, and yet remain highly 
attractive. 
The particular feature that strikes the visitor in 
the month of April is the extent to which the 
naturalisation of suitable bulbous subjects in the 
grass has been carried out, and the conspicuous 
success that has been attained in this direction. On 
every hand, wherever a suitable stretch of grass has 
presented itself, one finds the sward starred with 
Narcissi, Muscaris, and Tulips, following the Snow¬ 
drops and Crocuses of earlier spring. These sweeps 
of grass-set flowers have much to recommend them ; 
they break the montony of formally shaped beds, 
and long, straight borders, and they distribute more 
evenly the rich colours of the flowers instead of con¬ 
fining them within the comparatively limited area of 
carefully laid-out beds, caged in with wire fencing, 
round which the public marches as around the den 
of some curious animal. 
Not that beds are wanting, however, for their 
requirements are well looked after, but the garden of 
grass, old-fashioned in idea as Nature herself, and 
yet original in execution, claims the first attention. 
The wide avenue with its fringe of umbrageous 
Horse Chestnuts is a pleasant promenade on a sum¬ 
mer’s day, but amidst the fresher green of the 
peeping young leaves it is simply delightful, whilst 
the eye rests with a sense of complete approval upon 
the line of graceful Elms, also in their rudimentary 
spring dress, which flanks them on either hand. This 
avenue runs approximately north and south, and by 
its side are gathered the greater part of the flower 
beds proper. All these beds are cut out in the 
grass, and even the borders have grass verges, but 
the public is rigorously kept off the grass, or else the 
latter would scarcely look as fresh and green as it 
does. Gravel paths, clean, dry, and comfortable, are 
provided in plenty, however, and the beauties of the 
flowers can thus be observed from all points of view. 
Hyacinths, Tulips, and Narcissi have been freely 
utilised, and a few Wallflowers have been introduced 
here and there to break the monotony, but we were 
rather suprised not to find them in greater 
numbers. 
Of the Hyacinths used the deep blue Grand 
Monarch was exceedingly good. H. Gertrude, and 
H. Grandeur a Merveille in association looked well, 
but by far the prettiest thing in Hyacinths was a bed 
filled with the flesh-coloured Gigantea, ard the light 
blue La Peyreuse, the two forming a very aesthetic 
blend. 
Of the Narcissi Sir Watkin, Empress, Barri con- 
spicuus, Horsefieldii, and Emperor have all been 
planted in considerable quantity, and one of the 
sights of the park was a large triangularly-shaped 
bed filled with the last named variety, a few dark 
maroon Wallflowers being interspersed with them. 
Tulips have been exceedingly gay and bright, such 
varieties as Ophir d'Or, Keizer’s Kroon, and Proser¬ 
pine, being the favourite varieties. Proserpine has 
been especially good in both the beds and the various 
ornamental vases scattered about the park. 
The narrow ribbon borders which run parallel 
with the centre avenue and on either side of it, have 
been filled with great taste and judgment. The 
double crimson and double white Daisies have been 
employed as a groundwork, and out of them there 
stood, in relief as it were, showy blocks of Narcissi, 
Tulips, and Hyacinths of various sorts ; in fact to 
our idea these borders constituted the most effective 
part of the bedding proper. Several round beds 
filled with Polyanthuses in variety and Alpine Auri¬ 
culas were also rendering a good account of them¬ 
selves. 
- . f 
SWEET-SCENTED LEAVES v. FRA¬ 
GRANT FLOWERS. 
Mr.F.W.Burbidge, M.A., of Trinity College Botanic 
Gardens, Dublin, read an interesting paper on this 
subject before the Fellows of the Royal Horticultural 
Society, on the 26th ult. Mr. J. Hudson, of The 
Gardens, Gunnersbury House, Acton, occupied the 
chair. 
Before proceeding to discuss the merits of fragrant 
leaves as against those of flowers, the lecturer spoke 
of the widespread use of perfumes amongst the mem¬ 
bers of the human race. They had been employed, 
he said, by the sturdy Norman and the crafty Moor, 
by the Hindoo and the Aztec, and their uses had 
not in fact, been restricted to any age or clime or 
nation. Many of these perfumes had been obtained 
in some way or other from sweet smelling leaves, 
and many plants were grown expressly for the pur¬ 
pose of preparing perfumes from them. In Shake¬ 
speare's time all the old gardens were full of sweet 
herbs used by housewives and chemists in the mak¬ 
ing of potions, pomanders, sweet waters, etc. 
Botany, medicine, and chemistry were then in their 
swaddling clothes. It was the age of perfumed 
gloves and shoes, and perfumes and sweet-scented 
plants generally were in high favour. English 
literature abounded in reference to sweet smelling 
leaves. He wished to persuade gardeners to place a 
higher value upon plants having fragrant foliage, 
and to cultivate them as carefully as they cultivated 
others for their flowers. The scent of certain leaves 
was due to the presence in those leaves of essential 
oils, and the perfume was the vapour exhaled from 
these oils under the influence of heat and moisture. 
He distinguished between odours exhaled by floral 
and foliage leaves by describing the former as posi¬ 
tive, and the latter as negative. Flowers emitted 
their fragrance only at certain times, and this 
fragrance was given off spontaneously, whilst in the 
case of foliage leaves the fragrance was there during 
the whole life of the leaf; it was persistent, and in 
some cases was retained even after the leaf was dead. 
In one or two instances the fragrance of the dead 
leaf was more powerful that that of the living one, 
as for instance in the scented Cape Pelargoniums. 
The audience was invited to test this by means of 
the samples of dead and living leaves of some of 
these Pelargoniums which had been brought to the 
meeting by Mr. Hudson. Finally leaf odours were 
negative because they were not given off spon¬ 
taneously as in the case of floral leaves, but were 
apparent when the glands containing the essential 
oils were ruptured by pressure in the hands. 
Leaf odours and flower odours on the same 
plant often differed. Thus in the Orange the 
scent of the flowers was different from that of the 
leaves, and that of the leaves from that of the 
bark and wood. 
Discussing the value to the plant itself of the 
presence of these essential oils, Mr. Burbidge 
suggested that perfumes were an aid to fertilisation 
in that they served to attract insects in much the 
