Jnly 10, 1884. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
Cattleya Gaskelliana alba (D. B. Crawshay, Esq., Rosefield, Sevenoaks).— 
A lovely variety with large handsomely formed flowers, pure white except 
for the yellow throat and a tinge of purple in the centre of the lip. 
Cattleya calummata (Sir Trevor Lawrence).—One of the 0. Acklandise type ; 
sepals and petals narrow spotted with crimson, the lip Avith pale wings and 
an intensely rich crimson central lobe. 
Cypr'ipedium Curtisi (Sir Trevor Lawrence).—A handsome spscies, Avhich 
has been previously described. 
Medinilla Teysmanniana (Veitch).—A bold plant with fine leaves like 
M. magnifica ; the flowers are 1 inch across in a conical head, bright rose, 
anthers mauve. 
Indigofet a Jlorihunda alba (Veitch).—-A pure whits variety of this well- 
known shrub, the flowers in slender racemes G or 8 inches long. 
Carnation Celia (Veitch).—A bright clear pink self, full, and of good 
form. Free and vigorous in habit. 
Iris KcBnipferi Earl Granville (Veitch).—A grand flower, 8 inches in 
diameter, rich violet-purple with darker veins. 
Iris Kannpferi Princess Maude (Veitch).—Flower large, white, with 
yellow blotches at the base. 
Iris Koempferi Mary Anderson (Veitch).—A charming variety ; white, 
h purple pencilling, petals equal in size and rounded. 
v/itSinruBa purpurea (Veitch).—A Japanese species somewhat like S. palmata 
l(cse cymes of delicate rosy flowers, and neat five-lobed bronzy green 
leaves. Ve ry dwarf and free. 
Perpetual Carnation Martha (Duffield).—A very free and pretty variety. 
Yellow ground, with crimson and scarlet streaks. 
Delphinium Gloire de Nancy (Bealby).—A pretty double variety, with 
neatly formed flowers, mauve edged with pale blue. Very distinct and 
attractive. 
SciENTirrc CoMMiTTE.—Professor M. Foster in the chair. Lansia tibeticaj 
Hk. f. and T. —ilr.Loder exhibited this plant, figured in “ Hooker’s Journal,’ 
1857, but which does not appear to have flowered in England before; 
Ranunculus cortusifolius.—He also showed this fine species (“ Bot. Mag.,’ 
4625), and a white Orchis resembling 0. pyramidalis in form. It was referred 
to Mr. Ridley for examination ; it came from Rev. H. Crewe’s collection; 
also Gentiana bavarica, finely grown plants with deep violet-blue blossoms, 
and he also brought specimens of Plantago major and lanceolata with 
foliaceous bracts, a well-known menstrosity. 
Monstrous Geum rivale. —Mr. Boulger described a form of this plant Avith 
a foliaceous calyx, corolla of three rows of petals, stamens reduced in number 
and proliferous; instead of a pistil the prolonged axis bearing a normal 
flower. This form Avas described by Dr. Hill in 1758. 
Chlora perfoUata. —Mr. Boulger noticed that this plant opens its flowers 
at 0 A.M. and closes them about 4.30 p.M., and a specimen Avhich was placed in 
his vasculum Avith closed blossoms was found to be opened at the usual hour, 
though in the dark. 
^Ecidium Euphorbice. —Dr. Masters exhibited a specimen of E. cyparissias 
from Zermalt, the leaves of which were increased in dimension in consequence 
of the attack of this fungus. 
Deport on Potato Culture at Chisioick. —Dr. Masters reported that the 
second visit to Chiswick of the Sub-Committee had been made, and that, 
though the disease Avas present in the gardens, it had not yet reached the 
experimental plot. The second series were earthed-up in the manner as 
directed by Mr. Plowright. 
Puccinia Vincee .—Mr. W. G. Smith exhibited plants of Periwinkle 
attacked by this fungus, which does not as a rule appear to be very common. 
Honeydew —Mr. Bennett called attention to the fact that the Limes are 
very abundant in honeydew, and the question was again raised as to the 
part aphides play in its production. The general opinion (as expressed 
previously Avhen the question Avas raised) was that it is more due to the 
intense heat carrsing an alteration in the starch into a sugary substance. 
Indigofera tloribunda alba —This plant was exhibited by Mr. Veitch, but 
as it had not the peculiar irritability of the stamens characteristic of species 
of Indigofera as described by the Rev. G. HensloAV in the Journal of the 
Linnean Society, it aa'es referred to Dr. Masters to ascertain the correct 
name. 
Picea Nordmanniana Attacked by Aphis. —A horticulturist forAvarded 
branches of this tree attacked by aphis, and Avhich were described as com¬ 
mitting great destruction amongst plants of this species and also of Abies 
grandis. It Avas referred to Mr. MacLachlan for examination and report. 
Dried Dhubarb Stalks. —Mrs. Jones forwarded a sample of Rhubarb from 
which nearly all the juice has been expressed and dried. She recommends 
its use in Avinter as a preserve. It Avas referred to the Secretary for examina¬ 
tion and report. 
Hybrid Digitalis. —Mr. A. D.an sent specimens of a supposed hybrid 
between D. purpurea and D. lutea. The late Professor Henslow described a 
natural hybrid between these species, the blossoms of Avhich were decidedly 
intermediate in colour. Those sent by Mr. D, an appear to be much yelloAver 
and with less purple. It Avas given to the Rev. J. Henslow for examination 
and report. 
Monstrous Antirrhinum. —The seedling Snapdragon, “ RoAvsham Pet,” 
forwarded to the last meeting by Mr, James King of Aylesbury, who 
received a certificate for it, appears to have a tendency to the ‘ peloric” 
or regular condition. The calyx is quite normal. The corolla has the two 
lateral petals developing small labial yellow ridges, thereby imitating the 
anterior or lip petal. Each of the two posterior petals constituting the hood 
are bifurcated above, Avhile the corolla, instead of being personate and closed, 
is Avidely expanded, the lobes forming an irregular corrugated rim. The four 
stamens are abnormally twisted, and bear contabescent anthers. The position 
of the normally absent fifth stamen on the posterior side is occupied by two 
staminodia with petaloid crozier-shaped structures, somewhat resembling the 
petals of Aconitum, together Avith a short filiform structure between them; 
the pistil IS normal. 
THE GUM DISEASE IN PLANTS. 
Sir James Paget, Bart., commitnicated to the Medical Times recently 
the outline of some researches in connection with the contagion of gum- 
disease in plants undertaken by Dr. Beijerinck and lately published in the 
Royal Academy of Sciences at Amsterdam. The matter is of much interest 
and the substance is given as follows :— 
“The gum-disease (gummosis, gum-flux) is only too Avell knoAvn to all 
who grow Peaches, Apricots, Plums, Cherries, or other stone fruits. A similar 
disease produces gum arable, gum tragacanth, and probably many resins and 
gum-resins. It shows itself openly in the exudation of thick and sticky or 
hard and dry lumps of gum, which cling on branches of any of these trees 
where they have been cracked or Avounded through the bark. To any 
students of medicine or pathology Avho live within range of such trees Dr. 
Beijerinck’s observations may suggest some interesting researches. 
“ Dr. Beijerinck Aims induced to make experimental inoculations of the 
gum-disease by suspicions that, like some others observed in plants, it was 
due to bacteria. He ascertained that it is in a high degree contagious, and 
can easily be produced by inserting the gum under the edge of a Avound 
through the bark of any of the trees above named. The observation that 
heated or long-boiled pieces of gum lose their contagious property made it 
most probable that a living organism Avas concerned in the contagions ; and 
he then found that only those pieces of the gum conveyed contagion in 
Avhich, whether with or without bacteria, there were spores of a relatively 
highly organised fungus, belonging to the class of ascomycetes : and that 
these spores, inserted by themselA'es under the bark, produced the same 
pathological changes as did the pieces of gum. 
“ The fungus, thus detected, Avas examined by Professor Oudemans, who 
ascertained it to be a new species of Coryneum, and has named it Coryneum 
Beijerinckii. Its characters, which are minutely described, are chiefly that it 
has a cushion-like stroma, consisting of a bright brown parenchyma, on 
which numerous conidia stand on colourless, unicellular, and very slender 
stems, about as long as themselves. The conidia are small, cask-shaped, 
about one-thirtieth of a millimetre in length, and usually divided by slightly 
constricting septa into four cells, of Avhich the two terminal are longer than 
the two middle. From these c^•lls germinal filaments may proceed, from 
which are developed either yeast-cells, or brown thick-Avalled and many-celled 
mycelia. 
“ The inoculation experiments are best made by means of incisions through 
the bark of young branches of healthy Peach trees or Cherry trees, and by 
slightly raising the cut edge of the bark and putting under it little bits of 
gum from a diseased tree of the same kind. In nearly every instance these 
wounds become the seats of acute gum-disease, while similar wounds in the 
same or other branches of the same tree, into Avhich no gum is inserted, 
remain healthy, unless by chance gum be Avashed into them during rain. 
The inoculation fails only Avhen the inserted pieces of gum contain no 
coryneum. 
By similar inoculations similar diseases can be produced in Plum, 
Almond, and Apricot trees, and Avith the gum of any one of these trees any 
other can be infected ; but of many other substances which Beijerinck tried 
not one produced any similar disease. 
“ The inoculation Avith the gum is commonly followed by the death of 
more or less of the adjacent structures ; first of the bark, then of the wood. 
Small branches or leafstalks thus infected in Avinter, or in many places at 
the same time, may be completely killed ; but, iii the more instructive 
experiments the first symptom of the gum-disease is the appearance of a 
beautiful red colour around the wound. It comes out in spots like those 
Avhich often appear spontaneously on the green young branches of Peach 
trees that have gum-disease ; and in these spots it is usual to find coryneum- 
stromata, or mycelium-filaments. The colour is due to the formation of a red 
pigment in one or more of the layers of the cells of the bark. 
“ Butin its further progress the disease extends beyond the parts at which 
the coryneum or any structures derived from it, caii be found; and this 
extension, Beijerinck believes, is due to the production of a fluid, of the 
nature of a ferment, produced by the coryneum, and penetrating the adjacent 
structures. This, acting on the cell-walls, the starch granules, and other 
constituents of the cells, transforms them into gum, and even changes into 
gum the coryneum itself, reminding the observer of the self-digestion of a 
stomach. . . , , 
“ In the cells of the cambium, the same fluid penetratmg unites with the 
protoplasm, and so alters it that the cells produced from it form, not good 
normal Avood, but a morbid parenchymatous structure. The cells of this 
parenchyma, well known among the features of gum-disease, are cubical or 
polyhedral, thin-Avalled, and rich in protoplasm. This, in its turn, is trans¬ 
formed into gum, such as fills the gum channels and other cavities found in 
wood, and sometimes regarded as gum glands. And from this also the new 
ferment-fluid constantly produced,^ and tracking along the tissues of the 
branches, conveys the coryneum infection beyond the places in which its 
mycelium can be found.” 
SPORTS PHYSIOLOGICALLY CONSIDERED. 
{Continued from ymge 371, la.st vol.) 
An interesting discussion followed the reading of Mr. Talbot’s paper 
on this subject, in the course of which many important facts were 
enumerated. 
The Hon. Marshall P. Wilder said that Mr. Talbot had so systematised 
his facts in regard to physiology, and stated them in such a sensible way, 
as to make his paper a remarkable one. His method of accounting for the 
production of four different kinds of wood in the Pear tree, by the cell 
being matured in the wood formed, the speaker thought correct. Y e all 
knoAV hoAV cells are produced and conjoined, but he had not so aa ell under¬ 
stood the process by which sports are produced, and that AAdiether they are 
called hybrids or sports, the process is the same. He had had much 
experience in producing neAA’ varieties, and some sports AAdiich he has fixed 
may have come from such a union of cells as the essajdst had described. 
b. W. Lothrop said that he had been exceedingly interested m the 
paper. The subject is very complicated—as much so as anythuig m science, 
except that of soils. Many German AAndters seem to be trying to explain 
old mysteries by iieAA’ phrases. The moment you can produce a sport, you 
shoAV that you understand the laAVS Avhich govern it. cannot get 
positive evidence on the subject, avo may get negative. Ihere is no cer¬ 
tainty in regard to sports : AA'hen Ave arii\’e at certainty regarding them, 
