December 2, 1886. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
491 
other class of plants during the winter months. A few plants 
should be taken into a house with a temperature ranging between 
i>0 and 70° as soon as the leaves have fallen in the autumn, and 
at regular intervals be supplemented by others to keep up a suc¬ 
cession. When they have flowered they should be kept under 
glass till they have completed their growth, after which they can 
be planted in the open air. It is generally necessary to prepare 
soil consisting principally of peat to plant them in, for although 
I have, seen them flourish wonderfully well in a stiff clay, so 
capricious are they in regard to soil that it is never safe to plant 
them in ordinary garden soil till it has been clearly ascertained 
that they will thrive in it. 
Rhododendrons in variety and Kalmia rosea andcuneata are 
two of the best hardy evergreen shrubs for forcing purposes, 
and succeed well under similar treatment to that given to the 
Azaleas, with the exception that they should not be forced quite 
so early. Weigela rosea, when grown into nice bushy plants, 
lifted and brought on gradually, are beautiful objects when in 
flower, and I have seen some lovely wreaths made with its delicate 
flowers and a green ground of Maidenhair Fern. Lastly, but 
. , J n< ? means least, that good old border plant Dielytra specta- 
bilis is one of the very best of all hardy plants for pots, but it 
will not bear hard forcing. Pot early and bring on gradually, 
and those who have not given it a trial before will be both sur¬ 
prised and delighted with its sterling qualities for arranging with 
other plants when in flower. I have not included the well-known 
Spmea japonica in this selection, as I intend offering a few 
remarks concerning their treatment on some future occasion.— 
H. Dunkin. 
FORCING RHUBARB. 
I AM surprised your correspondent, “ A Working Gardener,” has not 
found a better method of forcing Rhubarb than that described at 
page 471. Here is a plan that will not take up a tithe of the labour, 
and prove more reliable. If instead of conveying cartloads of fermenting 
material to the Rhubarb ground, take up the required number of roots 
and place them on a bed of fermenting material in the manure yard or 
framing ground, and cover them with tubs or pots. The bed may be com¬ 
posed of dung and leaves, or the latter only, with sufficient litter to 
support them to a height of about 2 feet in severe weather and for early 
work; at other times half that height will do. The width of the bed 
need not exceed the diameter of the tubs more than a foot, and after the 
roots are placed on it they may be covered with soil, decayed manure, or 
spent Mushroom dung, and to support this round the roots the sides of 
the bed must be continued until they are as high, if not higher, than the 
crowns, in order to allow as much head space as possible in the tubs or 
pots. Forcing is done by placing the fermenting material as a lining 
round up to the level of the crowns at first, 1 1 be afterwards increased if 
necessary. When I have adopted this plan there was no time spent in 
preparing the fermenting material by turning it sundry times, but it was 
wheeled direct from the stables, and placed, a barrowload thick, round 
the bed without any further arrangement; and, as we selected the 
manure yard for our operations, most of the labour was done by the 
stablemen, and we had only to watch the trial sticks inside the tubs, and 
if too warm draw the material from the sides. In cold weather the 
longest litter was also thrown over the tubs to confine the heat and protect 
the tender sticks. 
On several occasions we have levelled a part of the manure heap and 
placed the roots on that, which reduced the labour of Rhubarb-forcing to 
that of taking up the roots and planting the same number of fresh ones. 
There is no preparation of fermenting material, no wheeling it to some 
distant part of the garden to the Rhubarb beds, and probably back again 
after forcing is over, and there will be no scalded crowns nor disappoint¬ 
ment at the produce not being ready at the right time, as the heat can be 
regulated with the same precision as if in a structure heated by hot water. 
I have found the crowns very obstinate in starting at this time of the 
year, even in well-heated places, but they readily respond if supplied 
with slight bottom heat. Stools of Rhubarb lifted in the spring, and 
placed on the ground level and packed round with half-decayed manure 
or litter, will be a fortnight in advance of those left in the ground, simply 
because their roots are acted upon by the heat of the sud, or, in 
other words, they are in a warmer medium than those in the ground.— 
CARNIVOROUS PLANTS. 
(Mr. Latham’s Lectu r e .—Continued from page 474.) 
In an interesting paper read by Dr. James Macbride before 
the Linnasan Society in 1815, remarked upon some observations 
made by him in 1810 and 1811 in America on some species of 
Sarracenias. from which the following is an extract—“In the 
month of May, June, or July, when the leaves of these plants 
perform their extraordinary functions in the greatest perfection, 
if some of them be removed to a house and fixed in an erect 
position, it will soon be perceived that flies are attracted to them. 
These insects approach the pitchers, and leaning over their 
edges appearto sip with eagerness something from their internal 
surfaces, and in this position they linger; but allured seemingly 
by the pleasure of taste, they enter the tubes, and the fly which 
has thus changed its position will be seen to stand unsteady, 
totters for a few seconds, then slips and falls to the bottom of 
the tube, when it is either drowned or attempts in vain to ascend 
against the points of the hairs. In a house much infested with 
flies this entrapment goes on so rapidly that a tube is filled in 
a few hours. The inability of insects to crawl over the points 
of the hairs I have often tested in the most satisfactory manner, 
while spiders descend into these tubes to prey on the entrapped 
insects, and ascend with impunity, but this is performed by the 
assistance of their threads.” 
I have quoted these interesting experiments rather fully, 
firstly as showing that insectivorous plants had attracted the 
attention of scientific men as early as the latter part of the last 
century and commencement of the present. Secondly, because 
it explains the peculiar properties of the secretion in some of 
these plants, and the stupefying power it has upon insects, and 
the power must indeed be a strong one when such a powerful 
insect as the cockroach is often found a victim in the pitchers. 
In speaking of Sarracenias at Belfast, Dr Hooker remarked— 
“ The tissues of the internal surfaces of the pitchers are 
singularly beautiful. They have been described in one species 
only, S. purpurea, by Dr. A. Vogl, but from this all other species 
which I have examined differ materially. Beginning from the 
upper part of the pitcher there are four surfaces characterised 
by different tissues, which I shall name and define as follows— 
1, An attractive surface, occupying the inner surface of the lid, 
which is covered with an epideimis stomata, and, in common 
with the mouth of the pitcher, with minute honey secreting 
glands. It is often more highly coloured than any other part 
of the pitcher in order to attract insects to the honey. 2, A 
conducting surface, which is opaque, formed of glassy cells, 
which are produced into deflexed short conical spinous processes, 
overlapping like the tiles on the roof of a house, and forms a 
surface down which the insect slips, affording no foothold to 
any insect attempting to crawl up again. 3, A glandular 
surface, as seen in Sarracenia purpurea, which occupies a con¬ 
siderable portion of the cavity of the pitcher below the con¬ 
ducting surface, and is formed of a layer of epidermis with 
sinuous cells, and studded with glands, and, being smooth and 
polished, these also afford a foothold for escaping insects. 
4, A detentive surface, which occupies the lower portion of the 
pitcher in some ca c es for nearly its whole length. It possesses 
no cuticle, and is studded with deflexed rigid glass like needle- 
formed hairs, which further converge towards the axis of the 
diminishing cavity, so that an insect once amongst them, is 
effectually detained, and its struggles have no other result 
than to wedge it lower and more firmly in the pitcher.” 
As will be seen by my remarks, Dr. Hooker speaks of the 
insect getting wedged into the pitcher, Dr Mellichamp of the 
house spider falling a victim to the fluid, Dr Macbride of the 
spider descending into the tube to prey on the entrapped insect, 
and ascending with impunity by the assistance of their threads. 
These statements at first sight appear to be contradictory, but 
in reality they are not so, each investigator having experimented 
on different species of Sarracenias. In S. purpurea its trap is 
formed so as to fill with rain, and always contains liquid, and 
insects are thereby rendered helpless. 
The white Sarracenia Drummondi, S. flava, and Darlingtonia 
californica have a most perfect hood-like protection against rain, 
and their tubes or pitchers contain no liquid, and are always drj’, 
and insects are in these species entrapped by the process of 
wedging as described by Dr. Hooker, and it is almost impossible 
to imagine mere complete insect traps than tht se. Dr. Hooker 
observes further that “ The fact that insects normally decom¬ 
pose in the fluid of all would suggest the probability that 
they all feed on the products of decomposition, but as yet we are 
absolutely ignrrant whether the glands within the pitchers are 
secretive or absorptive, or both; if secretive whether they secrete- 
water or a solvent; and if absorptive whether they absorb 
animal matter or the products of decomposition.” That insects 
are attractive in large numbers is very evident, and it is only- 
necessary to examine some of the tubes of Sarracenias, the 
pitchers of Nepenthes, the traps of Dionaea, or the leaves of 
Drostras to find them in large quantities. I have often found 
in these traps a quantity of the remains of such insects as cock¬ 
roaches, flies, ants, Ac., when these insects have been somewhat 
plentiful, and all in a state of decomposition. The colouring 
matter previously referred to found in the pitchers of some of 
the plants 1 have named, as well as in the traps of the Dionsea 
and the leaves of Droseras, is very beautiful when the plants are 
in vigorous growth and good condition. The colour in most of 
