February 27, 1886. 
THE GARDENING WORLD. 
413 
developed root-system, upon which, in fact, they merely 
depend for water. Of these, the first to be described 
were the Sundews, a genus of about 100 species, of 
which forty were natives of Australia, where they some¬ 
times clambered up to some height, whilst other species 
occurred over most portions of the globe, the com¬ 
monest of our three British species, Drosera rotundifolia, 
upon which Darwin’s chief experiments were made, 
growing also in the Himalayas. The family to which 
it belonged was related to the Saxifrages, and its 
structure was illustrated on the screen, under the 
microscope, by diagram, specimens, and a much- 
enlarged papier mache model. The tentacular exten¬ 
sions of the leaf secrete a viscid fluid most copiously 
during sunshine, which is at first neutral, but affords 
the most delicate known test for nitrogen. If touched 
by any substance containing nitrogen, even the 20- 
millionth of a grain of phosphate of ammonia, the 
tentacle bent over, carrying the fly or whatever it 
might he, to the centre of the leaf, and the secretion 
on all the tentacles at once became acid. In the course 
of some hours all that was soluble in the fly was 
digested. 
Careful experiments had shown that the product of 
digestion was absorbed by the leaf; and by taking a 
number of specimens and feeding half of them with 
beef, whilst excluding all insect food, Dr. Francis 
Darwin had shown that the fed plants weighed more, 
and produced more buds, flower spikes, fruit-capsules, 
and seeds than the others. A Portuguese plant 
(Drosophyllum), allied to the Sundews, was hung up 
by the peasants in their cottages to catch flies; 
whilst another allied genus (Byblis) had similar 
glands within the flower. The next type referred to 
was the Sarracenias or Side-saddle plants of western 
North America, introduced into cultivation in 1640, 
one species being half hardy. These plants, which 
are, as Linnaeus pointed out, related to the Water 
Lilies, have a cluster of pitcher-like leaves, furnished 
with a flange baited with honey to entice insects to 
crawl up it. The inner surface of the pitcher is partly 
smooth and slippery, partly studded with downward- 
pointed hairs, so that it practically resembles an 
eel-trap. The lid of the pitcher has sometimes colours 
resembling those of the flowers, or is furnished with 
semi-transparent patches against which insects might 
stun themselves, as birds often do against plate-glass 
windows. The internal glands secrete a liquid which 
does not show any digestive power, but is very wet— 
wetter than water, so that a fly falling into it would 
die of asphyxia, as it would in glycerine. Some moths 
lay their eggs in the putrefying mass of matter in the 
pitchers, and birds slit them open to get at the mag¬ 
gots, so that many leaves simply decay and manure 
the roots ; but others are believed to absorb the liquid 
products of decomposition. 
The lecturer next passed to Bladder-worts (Utricu- 
laria), submerged aquatic plants of world-wide distri¬ 
bution, furnished with little bladders, seldom a f in. 
long, which have been erroneously described as floats. 
They have trap-doors opening inwards only lined with 
with four-rayed hairs. They capture water-fleas, which 
they resemble as much as the statues of Memnon re¬ 
semble human beings, and which apparently only enter 
out of curiosity, and when in, die of overcrowding ; no 
true digestion occurring in this case, any more than in 
Sarracenia. In the allied genus of the Butter-worts, 
however, with a simpler structure, there is a higher 
physiology. Its rosettes of bright green leaves are 
sticky, and roll up their edges over captured flies ; and 
in Sweden are used for curdling milk. If the milk be left 
on the leaf, it is ultimately all digested, except a little 
oil; this being the strongest known digestion among 
plants. The next type was that of the true Pitcher 
plants (Nepenthes), of Borneo, India, and the Malay 
region, where the apex of the leaf is pitcher-shaped, 
and secretes a fluid from which the two ferments, 
azerin ” and “ droserin,” have been obtained, together 
with several acids and salts, by means of which a true 
digestion takes place, which is even more rapid than 
that of the pepsin of the pig. A yet higher organi¬ 
sation than this was that of the Venus’s fly-trap 
(Dionfea), a plant confined to some twelve square miles 
round Wilmington, in Carolina, but first described by 
Ellis in a letter to Linnreus in 1768, and experimented 
upon by Knight in 1818. It has a round leaf with 
tentacular teeth, but a dry surface. Towards the centre 
are six long jointed hairs, and when one of these is 
touched by a nitrogenous substance, the leaf shuts up 
like a rat-trap, theTmid-rib acting as^a hinge. This 
movement is accompanied by a deflection of the normal 
electric current, present in all living beings ; and this 
current is found by Professor Burdon Sanderson to be 
conveyed along the protoplasm of cells of the leaf, not 
along the veins. When a leaf closes on a fly, a copious 
secretion, in which formic acid has been detected, is 
poured out, running in some cases for as much as nine 
days, though generally completing the digestive process 
in about twenty-four hours. 
The leaves of the_ Drosera and Dioncea seldom eat 
more than two or three meals, old leaves becoming 
inert. The last plant referred to was Aldrovanda, a 
rootless, submerged plant, found in Queensland, Bengal, 
and the south of Europe, with its leaves in whorls of 
six, edged with teeth and having sensitive hairs over 
the central part of their surface, and four-rayed ones 
near the edge. Darwin spoke of it as “an aquatic 
Dioncea ” ; but it had been suggested that these four- 
rayed hairs might absorb the liquid products of decay, 
as in Utricularia, in which case the plant would com¬ 
bine in itself the characters of the two physiological 
types. Alluding to other cases in which glandular 
structures have been alleged to absorb organic matter, 
such as the floral glands of the Grass of Parnassus and 
of the Christmas Rose, in which the characteristic 
“aggregation of the protoplasm” takes place, which 
was first pointed out by Darwin, as an accompaniment 
of absorption, in the tentacles of Drosera, the lecturer 
suggested that glands not usually absorbent might be 
so occasionally. 
--—i- 
HORTICUL TURAL S OCIETIES. 
Aberdeen Horticultural Association.— 
The usual monthly meeting of the members of the 
Aberdeen Horticultural Association was held on the 
evening of the 19th inst. in the Christian Institute, 
Aberdeen, Mr. Harper (president) in the chair ; there 
was a large attendance. A paper on the propagation 
of Roses was read by the secretary on behalf of Mr. 
Innes, gardener, Blairgowrie, and a short discussion 
followed. The secretary also read a paper from Mr. 
Forrest, gardener to the Earl of Aberdeen, on the con¬ 
struction of fruit and vegetable gardens. Discussion 
followed, and both gentlemen were awarded the thanks 
of the society for their papers. Mr. Henderson, Cults, 
on behalf of a committee appointed at a former meeting, 
submitted a report recommending the formation of a 
benevolent society on the lines of the United Horti¬ 
cultural Benefit and Provident Society, London. 
Having read several of the rules of that Society, and 
explained its objects, Mr. Henderson pointed out that 
unless a hundred members were obtained it would be 
useless thinking of forming such a society in Aberdeen¬ 
shire. On the motion of Mr. John Robson, it was 
agreed that a remit be made to take steps to enrol 
members. An extensive collection of botanical speci¬ 
mens, sent by Mrs. Farquharson, of Haughton, were 
explained with the aid of the microscope by Mr. John 
Roy, secretary of the Aberdeen Natural History Society. 
A vote of thanks to the president terminated the pro¬ 
ceedings. 
Manchester Horticultural Improvement. 
—February 18th .—At the usual fortnightly meeting of 
this society, held on the above date, Mr. Bruce 
Findlay, President, in the chair, Mr. T. W. Stansfield, 
of Sale, read a paper on “Modes of reproduction in 
some of the lower orders of plants.” The chairman 
said they were aware that there was all but one natural 
mode of reproduction or propagation of plants, that is 
by seeds or spores ; all other modes, as striking from 
cuttings, budding, grafting, or division, are artificial ; 
yet the only way of perpetuating many kinds is by 
adopting the artificial mode of increase, and but for 
this mode many valuable varieties of plants would be 
lost to us, inasmuch as they do not come true from 
seed. The class of plants to be brought under their 
notice that night are replete with interest and wonder, 
and notwithstanding the little attention they commonly 
excite, they are important objects of study, inasmuch 
as they pave the way to the higher developments of 
vegetable life. However much art may, for convenience, 
reduce the productions of nature to isolated groups and 
divide them into separate sections, and although 
relatively distinguishable, they are not absolutely 
separable, for, however diverse the distant members 
may appear, they are all intimately connected and 
essential to each other, and form in their respective 
subordinations but integral parts of one harmonious 
whole. 
Mr. Stansfield said he assumed that all present 
were more or less acquainted with that peculiar sub¬ 
stance called protoplasm, which Professor Huxtable 
has described as the physical basis of life. Wherever 
there is life there is protoplasm, and the simplest forms 
of life are little bits of protoplasm. All forms of repro¬ 
duction consist in the splitting up of protoplasm, and by 
means of the black board he demonstrated the modes 
of reproduction by this splitting up of protoplasm into 
two or more pieces. In the next place he described the 
reproduction which takes place by the mixture of one 
portion of protoplasm with another, which he called the 
sexual process. He then explained the process of 
reproduction in Ferns by means of this intermingling 
of protoplasm. 
The Chairman at the close of the lecture, said 
Mr. Stansfield had treated his subject in a scientific 
manner and perhaps some of the gardeners present 
were asking themselves the question “Cui bono”— 
What’s the good of it all ? Franklin once put a counter 
question. What’s the use of a baby ? for no one will 
venture to inquire what is the use of a man. Ferns 
have spores little differing from those of Mushrooms and 
of mosses, and, like them, they are most prolific, for a 
single frond has been computed to produce upwards of a 
million spores. So minute are the reproductive spores 
of Ferns that their existence was for a long time doubted, 
and before microscopes exposed them to our sight 
this belief was common, and many references are made 
to it in our oldest writers. Shakespeare, in allusion to 
this then popular opinion, observes, “We have the 
receipt of Fern seed ; we walk invisible.” However, if 
the lecture only awakened in them a desire to examine 
into the structure and existence of these plants, they 
would not have met in vain. Mr. Butterworth moved 
a vote of thanks to the lecturer, which was seconded by 
Mr. Griffiths Hughes, and adopted. Mr. Stansfield in 
reply to a question whether it was possible to cross- 
fertilize Ferns, said it is not only possible, but often 
takes place. It cannot be done in the same way as by 
taking the pollen of one flower and putting it on that 
of another ; the only way in which such fertilization can 
be effected is to put the spores of the Ferns in such a 
condition that they can fertilize themselves. 
National Chrysanthemum.—At a well at¬ 
tended meeting of the general committee of this society, 
held at the old Four Swans, Bishopsgate Street, on 
Monday evening, the secretary, Mr. William Holmes, 
reported that all the gentlemen elected at the previous 
meetings to act as judges at the society’s shows this 
year had accepted office, and that it had been arranged 
that the September show should be held on the 9th and 
10th; the great annual Chrysanthemum show on 
November 10th and 11th, and the exhibition of late 
blooms on January 12th and 13th. The suh-conunittee 
appointed to frame the schedule, reported that having 
well considered the probable income and expenditure 
of the society for the year, had arranged for prizes to 
be offered to the amount of £75 at the September 
show ; £170 at the November exhibition ; and £50 in 
January ; independent of special prizes, and sup¬ 
plementary ones given by the Aquarium Company. 
After some discussion, principally bearing on the 
difficulty of adequately defining a Japanese Anemone, 
the recommendations of the schedule committee were 
agreed to. At the September show, besides early- 
flowering Chrysanthemums, there will be classes for 
Dahlias, Gladioli, &c., and in January, Cyclamens, 
Primulas, Solanums, and hardy ornamental plants will 
be invited. 
Crockham Hill Gardeners’ Mutual Im¬ 
provement.—The members of this useful and some¬ 
what recently established association, met on the 16th, 
under the Presidency of Mr. T. Stephens, when the 
Secretary, Mr. H. Finn, read a good practical paper on 
the cultivation of Borecole, which was much appreciated 
by all present. In reply to a cordial vote of thanks, 
Mr. Finn alluded to the present depressed state of 
agriculture, and the necessity that arose therefrom of 
cottagers improving their methods of cultivation, and 
increasing the number of vegetables grown, and ex¬ 
pressed a hope that the Society would be the means of 
bringing about such a desirable result. Several sub¬ 
jects of interest to the members were exhibited, includ¬ 
ing Blenheim Orange Apples, Beurre Bretonneau Pears, 
Cottagers’ Kale, Chinese Primulas, and Allium neapoli- 
tanuin, &c. 
--- 
QUESTIONS AND ANSWEKS. 
Gas and Vegetation.— Can any of your readers refer me to a 
case of plants being injured in a nursery in close proximity to a 
gas factory, or to any legal decision bearing on such a case.— A. 
Sulphide of Potassium. — C. J. L.: The manufacturers are 
Messrs. P. Harris & Co., Bull Ring, Birmingham. 
Nursery.— T. D.: At Holloway, in the north of London. The 
nearest railway station is Upper Holloway ; and Finsbury Park, 
on the Great Northern main line, and Kentish Town on the 
Midland and Great Eastern system, are within about fifteen 
minutes’ walk. 
Stove Temperatures.— R. A.: The day temperature should 
range about as follows :—January, 65°; February, 65° ; March, 
70° ; April, 70° to 75°; May, June, July, and August, 70° 
to S0°; September, 70° to 75°; October, 70° to 75°; November, 
65°; December, 65°. The night temperature should always be 
not less than 5° lower. Necessarily you must have in the sum¬ 
mer months a higher day temperature by sun heat. 
Mushroom House. — G . S . : With walls so thick, and a loft 
overhead, no artificial heat would be required. The best plan, 
if you want to fully utilize the space, would be to have a series 
of beds in tiers, from 1 ft. to 15 ins. deep, but it is impossible to 
say what weight of produce you will get from such a building, 
