January 4, 1890. 
THE GARDENING WORLD. 
just the same as animals. The dust or “stirabout ” of 
the atmosphere chokes the breathing pores in the 
plant just as it does ours, and if they are not cleansed 
the natural economy is disturbed, and suffering follows. 
Thus we find that smooth and rather large-leaved 
plants—Planes, Aucubas, Camellias, Myrtles, Ficus, 
and the like, always are found to succeed better in the 
smoke of towns than the small-leaved and woolly¬ 
leaved plants, as these collect the dust and hold to it. 
Before large plants are taken to their winter habi¬ 
tation, it is well that each be laid upon its side, and 
thoroughly cleansed by means of the syringe and other 
ways, making the foliage as clean as possible. They 
should be laid upon a clean pavement or a garden mat. 
The plants being cleaned there is a point or two to be 
considered in the matter of arrangement. In placing 
the plants in the house, give those most likely to be 
affected by cold and draught the warmest part of the 
structure. The fact remains that the more hardily plants 
are treated from this time, the less likely will they be to 
sustain injury through the winter; and hence, observing 
the rules laid down, it will be manifest that, secured 
from frost and cold draughts, the more air is given the 
better it will be for the plants. There is no occasion 
to apply fire-heat until it is necessary to exclude frost, 
and then no more should be used than is requisite to 
maintain the desired temperature.— It. D. 
-*>$<-- 
THE FIRST HYBRID PASSION 
FLOWER. 
The Passion Flower, known in cultivation under the 
name of P. cceruleo-racemosa, is believed to be the 
first artificial production in the genus. It is the result 
of hybridising P. racemosa with pollen taken from the 
common Passion Flower (P. ccerulea). This was 
effected in 1819 by Mr. Thomas Milne, of the firm of 
Messrs. Whitley, Brames & Milne, of Fulham. 
The female parent (P. racemosa) is best known in 
gardens at the present day under the name of P. 
princeps, a name given to it by Messrs. Loddiges & 
Sons, of Hackney, in 1817 ; but it had previously been 
described in 1815 by Professor Brotero, of Coimbra, 
under the name of P. racemosa, which is, therefore, 
the true one by right of priority. The latter had 
never been known to fruit in gardens of its own accord, 
and this character it still retains to the present day as 
far as I am aware. Flowers are generally produced 
in great abundance, but they fall away soon after 
expansion. It, however, readily set fruit when the 
pollen of P. ccerulea was applied to it ; and the oval 
fruits ripened off to a yellow colour, after attaining a 
length of about ins. Of thirty fruits or thereby 
that were thus obtained, only about two contained 
fertile seeds, and only seven plants germinated. 
The first that flowered was that to which the name 
P. cceruleo-racemosa was applied. The practice of 
combining the specific names of the two parents is 
therefore a very old one, and although it may be 
difficult to trace who first adopted the plan, yet it is 
certain that it was done as early as 1809 by Signor 
Carlo Bellardi, of the University of Pavia, at Milan. 
It is the rule also, as in this case, to put the name of 
the male parent first. An examination of the plant 
shows that it partakes largely of the characters of P. 
ccerulea, both in the three to five-lobed leaves, the 
solitary axillary flowers, and in the structure of the 
corona, which makes such a prominent feature in the 
flowers of all the Passifloras. 
The colours exhibited by the flowers of the hybrid are, 
however, different from those of either parent. The 
inner surface of the sepals and petals of P. ccerulea are 
whitish; those of P. racemosa are crimson-red or 
scarlet, while in the hybrid the petals and the inner 
face of the sepals are pale purple. Blue and white are 
prevailing features in the corona of P. ccerulea, but 
there is a certain amount of purple near the base. 
The lower third of the outer two series of segments in 
P. racemosa are white, the rest being purple. In the 
hybrid this arrangement is reversed, for the basal half 
is a rich, deep purple, and the upper half white. 
The above characters show that the male plant, con¬ 
trary to the general rule, has influenced the hybrid in 
many impoitant particulars. The racemose inflorescence 
of the female parent is wholly suppressed, and instead 
of the leaves having three short, broad lobes, they have 
three to five narrow ones as in P. coerulea. The corona 
is richer in colour than either parent, but except in 
colour the different parts are similar in form and length 
to those of the male, and like the latter the bracts are 
persistent, while they fall away from the racemose in¬ 
florescence of P. racemosa. The stem, stipules, structure 
of the flower, and leathery character of the leaves are 
those of the last named. 
The common Passion Flower is hardy against a south¬ 
east or west aspect wall in the south of England, and 
often fruits abundantly in such positions, but P. 
racemosa requires the treatment of an intermediate 
house or stove. The hybrid flowers continuously and 
most profusely for many months in the year if grown 
in a greenhouse and trained under the rafters. It is a 
strong-growing subject, and must occasionally be rather 
severely cut back to keep it within reasonable bounds. 
The long, pendent shoots loaded with flowers and buds 
in various stages of development are, however, very 
beautiful. 
---- 
SEASONABLE NOTES ON PRO¬ 
PAGATING. 
With the opening of another year, a very busy time is 
approaching ; therefore, all necessary cleaning and 
repairing should be done in the propagating house, or 
in those parts of it that are not occupied, preparatory 
to the busy spring time, which will be here shortly, 
and will require all the energies of a staff to keep pace 
with it. It will be found necessary to renew plunging 
material in most of the cases, and nothing can be better 
for this purpose than coco-nut fibre refuse, which is 
both clean and sweet, and better adapted to the purpose 
than anything else that can be found. Lime-wash all 
cases before the plunging material is put into them 
again ; it helps to keep things sweet, as well as to 
destroy any germs of insect life that may be lurking 
about in crevices or corners. Too much haste in 
getting in some soft-wooded cuttings at the commence¬ 
ment of the year has many times ended in failure ; 
therefore, it is much better to have all the preparations 
needed seen to first, leaving the cuttings alone to 
obtain more strength with the advance of the month, 
when they will root much better than if put in so very 
early. 
Dahlias. 
Any propagator who miy have a quantity of Dahlias to 
get ready for the spring, will be wise to overhaul the 
old roots of this stock of plants, to see that the crowns 
are in a satisfactory state, or else he may find when the 
time conies for starting them into growth, that the 
crowns will be rotten and only the tubers left alive ; 
these will be no good without some part of the crown is 
in a living state. Better cuttings may always be 
obtained from ground roots than from pot roots, 
although the latter are very serviceable to fall back 
upon in case of accident to the ground roots. 
Caladiums. 
As the month advances it will be well to overhaul the 
stock of Caladiums, aad those that require to be 
increased should be taken in hand, so that they may be 
out of the way before April. Where an increase is 
necessary, the corm or root-stock must be cut up into 
as many pieces as there appear to be eyes that are 
likely to start into growth. After cutting through, it 
will be well to smear the wounded parts over with dry 
powdered charcoal, potting at once into some sandy 
peat and loam, and placing in a brisk bottom heat, but 
not watering the soil until such time as the wounds 
have healed over, or some signs of life become visiblo, 
when they will soon fill the small pots with roots, and 
require to be potted on and placed amongst the general 
collection of stove plants. 
Achimenes and Gloxinias will also require attention 
now should any addition be needed to the stock. 
Seed sowing of Gloxinias and Tuberous Begonias must 
commence where the plants are expected to flower 
during the present season, the progress of the young 
plants at first appearing slow, but in the long run the 
early-sown plants come in first. 
The seed of these plants is naturally very small, and 
I find it germinates best when sown upon a very even 
surface of soil that has been well soaked a few hours 
previous to sowing the seed ; this saves the necessity 
of watering the pots overhead with a fine rose water 
pot, which in careless hands does more mischief than 
good by swilling all the seed to one side of the pot or else 
washing it away altogether. Cover over as soon as sown 
with a piece of glass, again covering this with a piece of 
brown paper to exclude the light from the surface of 
the soil. Germination will soon take place under these 
conditions, and it is more satisfactory than covering 
the seed over with soil or sand. In all cases the pots 
should be stood over a warm bed, or else should be 
plunged in a brisk bottom heat. 
Other kinds of plants, such as Fuchsias, Heliotropes, 
&e., &c., where a number of cuttings will be required 
from them, should have attention at once by placing 
plants of the sorts most required into heat, using the 
syringe freely about them to induce them to break 
freely into growth. — Varax. 
27!) 
SERMONS IN STONES. 
( Continued from, p. 260). 
In the order of succession upwards wo come to the 
Old Red Sandstone, which consists of red and grey 
sandstones frequently mottled or variegated, slaty marls 
and shales. The maximum depth of this system in 
south Wales is 10,000 ft., but in Scotland it reaches 
16,000 ft. The rocks when exposed crumble down, 
forming rich red soils. Some of the richest agricul¬ 
tural or horticultural soils in the island occur upon the 
Old Red Sandstone, such for instance as the fruit 
orchards of Herefordshire, Worcestershire and Devon¬ 
shire, and the richer corn-producing districts in Scot¬ 
land, including East Lothian. The value of the 
soil i3 determined by the occurrence of the leading 
constituents of a good soil, namely, clay, sand and 
lime, while many fossil remains are also found, chiefly 
fishes. The beds of concretionary limestone that occur 
amongst the sandstones in places, determine the success 
of the Herefordshire orchards. 
The Carboniferous system includes the mountain 
limestone, millstone grit, and coal measures proper. 
The mountain limestone consists of hard blue limestone 
rock giving rise to a thin soil, which, however, supports 
a short sweet herbage. Where the limestones come in 
contact with clay shales, the result is a naturally rich 
and productive soil under good tilth. The millstone 
grit affords only worthless and unproductive soils, often 
rising into hills covered with heath and boggy moor, 
whereas the limestone hills are covered with grass to 
the top. The coal measures consist of alternating 
strata of grey sandstone, clay shales and coal. Where 
the sandstones come to the surface they give rise to 
hungry, unproductive and often almost worthless soils. 
The shales crumble into heavy clay soils, capable of 
producing heavy crops, provided a large amount of 
labour and capital is expended upon drainage and 
tillage. The Permian or Magnesian Limestone system 
overlies the Carboniferous, and comes to the top, forming 
a strip of land extending from Durham to Nottingham, 
producing a naturally poor soil, but capable of 
improvement. 
Secondary or Mesozoic Strata. 
The New Red Sandstone consists of red sandstones and 
red marls, extending to a depth of only 500 ft. in 
England, but as much as 1,600 ft. in Scotland. In 
England the system comes to the surface and covers 
a large extent of the central portion of the country 
extending in a narrow strip northwards to Dumfries. 
The soil formed by the crumbling of the rocks is rich 
in plant food, easily and cheaply worked, and, as a 
rule, very highly rented. In whatever other part of 
the world the New Red Sandstone appears at the 
surface the soil is highly productive. The Lias 
immediately above this system consists of heavy, 
difficultly workable, blue clay soils, forming a narrow 
strip extending from the mouth of the river Tees in a 
south-westerly direction to Dorset. Like other clays, 
it only requires drainage to render it productive. At 
present it is occupied by rich old pasture lands. 
Above the Lias comes a series of limestones termed 
the Oolitic, the latter name being derived from the 
characteristic features that prevail more or less through¬ 
out the series. Oolite comes from the Greek oon, an egg, 
and lithos, a stone, in reference to the material of the 
rocks being made up of small particles of calcareous 
matter cemented together, resembling the egg or roe of 
fish. The series is divided into the Lower, Middle, 
and Upper Oolite. The Lower or Bath Oolite consists 
of limestone, calcareous sandstone and clay, and the 
quality of the soil overlying this system depends upon 
whether the different materials occur alone or are 
mixed. The clays are in pasture, while the rest is 
more or less fertile and inexpensive to work. The 
Middle Oolite consists of the dark blue adhesive Oxford 
clay, with calcareous grit above. The clay is most 
difficult to work, becoming extremely hard in dry 
summers, and most adhesive in wet ones. The Upper 
Oolite also consists of clay and calcareous sandstones. 
Where the two kinds mix, an excellent soil is the result. 
The Oolitic formations come to the surface and form a 
broad strip of land extending from above Whitby, in 
Yorkshire, to Portland, in Dorset. 
The Cretaceous system consists of clay, sands some¬ 
times hardened, and chalk. The Lower Cretaceous 
includes the Weald Clay occurring extensively in Kent 
and Sussex, forming the wet clay lands of those 
counties, readily improvable by drainage, and the 
Lower Green Sand. The Upper Cretaceous includes 
the Gault, a marly and blue tenacious clay, the Upper 
Green Sand, and the Chalk. The Green Sands, both 
upper and lower, but especially the upper, contain 
large quantities of nodular bodies—the so-called copro- 
lites of commerce—consisting of organic remains that 
are rich in phosphate of lime. For this reason, to a 
great extent, is due the valuable character of the soil 
overlying the Green Sands.— J. F. 
