442 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER 
[ November 18, 1881. 
eupeiba and C. exoniensis, with pale lilac sepals and petals ; the lip extremely 
rich crimson. Very handsome. 
Oncidiuni mcurvum album (W. Lee, Esq., Downside).—A pure white 
variety of this distinct Oncidium, exactly resembling the type in the narrow 
twisted sepals and petals. 
Ipoyncca Thomsoni (Veitch).—An excellent form, with trifoliate leaves 
and pure white large abundant blooms. 
Viburnum Tinus aureo-marginatuvi (C. Lee & Son).—A prettily varie¬ 
gated form of neat compact habit; the leaves narrow and distinctly margined 
with bright clear yellow. 
Cupressus Lawsoniana Fleeti (G. Fleet, Uckfield).—A very distinct and 
beautiful variety in the way of gracilis in habit, but with an abundant 
silvery variegation at the base of the short branchlets, which gives the 
whole plant a fine glaucous appearance. It is one of the best varieties that 
has been yet obtained. 
Caraguata angustifoUa (Veitch).— A Bromeliaceous plant, with tapering 
narrow leaves, yellow flowers, and bright coral red bracts ; very graceful 
and attractive. 
Semcio pulcher (Eoyal Horticultural Society).—Several plants of this 
handsome and now well-known species were exhibited from Chiswick, the 
rich purple flower-heads being of great size. 
Chrysanthemum Criterion (Veitch).—A well-known Japanese variety ; 
very large, the florets flat or tubular, orange-yellow ; handsome. 
Chrysanthemum roseum (Veitch).—Japanese; bright rose, 
crimson, flat florets ; full and substantial. 
Chrysanthemum La Bien Aimee (Cannell).—Japanese; white, the lower 
florets with a tinge of purple, something in the way of Mdlle. Lacroix, the 
florets fluted and irregularly cut at the tips. 
Chrysanthemum CulUngfordi (Cannell).—A most handsome variety with 
broad flat florets, intensely rich dark crimson, the under side bronze-tinted ; 
full, fine, and of good form ; a large reflexed variety. 
Chrysanthemum Star of Whijke (Cannell).—A large Pompon, pure white ; 
fine and good. 
Chrysanthemum Anais (Laing).—Pompon. Small bloom, naiTow cut 
florets, pale yellow, with a pink tinge. 
Chrysanthetmim La Purete (Laing).—Japanese. Very long flat pure 
white florets, large blooms ; free and handsome. 
Zonal Pelargonium Le Cygne (Cannell).—A double white’variety with 
well-formed blooms, fine truss, good habit. 
Scientific Cojimittee. —Mr. Loder in the chair. 
Weevils Attaching Orchids. —Mr. Pascoe exhibited specimens of Acytho- 
peus, n.sp., from Borneo and elsewhere in East Indies, imported with the 
Orchids which they attacked. 
Orchids, Photograph of. —Mr. Smee exhibited photographs of Orchids 
as growing during the summer out of doors. They were taken into the 
house in October. Several had flowered during the three mouths they 
were out. 
Knot in Birch. —Mr. McLachlan showed solid woody knots, apparently 
embryo buds of 1 to inch in diameter. 
Cockroaches in the Palm Stove. —He also showed specimens of Peri- 
planeta americana occurring at Kew, received from Mr. Dyer. 
Masdevallia Leaves Diseased. —Mr. Smith showed specimens badly 
infested with Protomyces concomitans growing in the intercellular spaces. 
Mr. Boscawen thought it might have been attacked by a thrips. Mr. Smith 
had not observed any. Mr. McLachlan remarked that Portschinsky said 
that thrips only attacked unhealthy plants, but could not assent to the 
statement. 
Litium auratum Bulhiferous. —Mr. Wilson brought stems of this Lily 
provided with aerial bulbs hke the bulhiferous section. He remarked that 
L. longifolium often bears them. He stated that the frosts of April cut 
down the young stems of L. speciosum, but the bulbs left in the ground 
appeared to be larger, with bulbils also in some cases, notwithstanding the 
foliage being unformed. 
Diseased Pear Stems. —Mr. Murray reported on these, and said that 
hough some fungus was present he could not account for the injury. He 
thought younger specimens might be studied with advantage. 
Experiments at Chiswick to Test the Jensenian Moulding of Potatoes .— 
The report was sent by Dr. M. T. Masters, embodying the results of experi¬ 
ments carried out under the superintendence of the Sub-Committee. The 
chief conclusions arrived at were as follows :—1, Earthing up increases the 
period of vegetation and amount of produce; “ except in one instance 
(whole tubers, bent tops, Adirondack) the produce of the sections earthed 
up for the longest period is markedly in excess of that yielded by the 
sections earthed up for the shortest time.” It may be also observed that 
tubers not earthed up at all (control rows) yielded the largest quantity, but 
the worst in quality and most liable to disease. 2, Bending the haulm 
reduces the produce, but conclusions from these experiments cannot be 
accurately deduced, “ nor is it p)racticable to dissociate the effects of the 
bending from those of earthing up.” [Mr. Plowright observes that bending 
should not be done while the Potatoes are in blossom, but before July 15th 
and after 28rd no deterioration of the tubers occurred in experiments in 
Holland.— Gardeners’ Chronicle, April, 1884.] Moreover, the bending the 
tops is practically almost impossible from the quantity of foliage and the 
quick recovery of position. 3, The effect of cutting the tubers is shown in a 
marked deficiency of produce compared with the result from using whole 
tubers, there being a difference of about 10 lbs. in favour of whole tubers of 
Recorder and of 12 lbs. in the case of Adirondack. 4, Amount of disease. 
So trifling has been the attacks of Peronospora that, as far as any results 
could be obtained to test the Jensenian method of moulding, they are practi¬ 
cally nil. Many Potatoes were, however, characterised by reddish spots 
dispersed through the tuber, the cause of which is at present inexplicable. 
Tubers thus affected are called “suspects” in the report. The true Potato 
disease was almost exclusively confined to Recorder, and to tubers earthed 
up a proportionately short time. In the control rows, however, both varie¬ 
ties were affected. It was moved by Mr. Grote and seconded by the Hon. 
and Rev. Mr. Boscawen, that the same Sub-Committee be instructed to carry 
out a repetition of the experiments at Chiswick in 1883 to test the Jensenian 
method of protecting Potatoes from the attacks of Phytophthora. 
Potato Diseases. —A communication was read from Mr. Plowiight, 
which the following is an abstract. The chief diseased conditions are :— 
A, Diseased conditions arising from causes affecting the growth of the plant 
itself: (1) green tubers, (2) hollow tubers, (3) supertuberation. B, Diseased 
conditions arising from causes external to the plant: (1) the “Potato 
disease” (Phytophthora infestans), (2) wet rot (Bacillus amylobacter. Van 
Leigh), (3) dry rot, (4) scab, (5) spotting or mottling. Passing over A (1) 
as unimportant, the author observes that hollow tubers are a reversion to 
the normal state of aerial stems. The cells bordering the cavity have no 
starch, and are suberised. Tubers diseased by Phytophthora are characterised 
by being first affected on the surface, as Kiiln pointed out in 1859, as the 
zoospores attack it through the epidermis. The author quotes the view that 
the mycelium penetrates the tuber by the haulm, a view held in this country 
but not on the continent, and he remarks that the former view is proved by 
experiments, whereas the latter has not been experimentally tested, except 
that when cotton wool is wrapped round a portion of the stem, and all the 
rest artificially infected with the disease, the protected part alone remains 
entirely free from mycelium. The deep brown and opaque places, are not 
diffused but harder and drier than the rest. The cultivation of the fungus 
is easy, but it soon loses the power to produce conidia. The browning 
appears in two days at a temperature of 75°, but after longer periods with 
lower temperatures. Wet Bot. —Potatoes diseased with this decay in pits 
and in ground. It is caused by Bacillus amylobacter. This microbe attacks 
the cell-walls. It is very infectious. To cultivate Phytophthora without the 
Bacillus it is necessary to desiccate the slices charged with the former, as 
the latter then dies, or is quiescent. Dry Bot. —This occurred to a great 
extent in Germany in 1830, and has been common there ever since 1842. 
The Potato is “dead-looking,” and has brownish or bluishy spots within—in 
old stages the interior is a mass of yellowish white and friable substance. 
It has not been noticed to any extent in England. Scab. —This is unimpor¬ 
tant. The cause apj)ears to be unknown; but the author is inclined to 
think it is an effort to form cork to prevent the entrance of fungi. 
Spotted and Mottled Tubers. —These spots differ from those due to 
Phytophthora—1, being inside the tubers; 2, they are neither so opaque nor 
BO dry nor deep in colour. No trace of a mycelium was to be found, and no 
conidia could be obtained by cultivation by De Bary, Eostrap, Jensen, 
Plowright, Murray, or Henslow. Mr. Jensen suggested it might be an in¬ 
cipient stage of dry rot, but Kiiln negatives this view. Mr. Plowright adds 
that a crop was unsaleable this season, as it cannot be foretold how many 
tubers may not be attacked. Mr. Plowright also forwarded specimens of 
tubers—1, diseased by Phytophthora through the epidermis; 2, mottled; 
3, wet rot as it occurs naturally with Phytophthora ; and 4, artificially 
induced on sound tubers ; 5, Spicaria Solani ; 6, Acrostalagmus cinna- 
barinus. He also sent copies of Rencke and Berthhold’s figures of Bacteria, 
showing starch grains in the process of dissolution of Bacillus Amylo¬ 
bacter. With reference to Mr. Plowright’s statement that mycelium w'as 
not found in the part protected by cotton wool, Mr. W. G. Smith reported 
that he had carefully examined the experimental specimens forwarded to 
the last meeting, and had found mycelium throughout the stem, quite as 
much under the wool as elsewhere. Mr. Plowright alluded to Mr. Murray’s 
experience in getting the mycelium to penetrate the tough skin of 
Champions as corroborating De Bary’s statement. Mr. Murray said that 
it was only in the case of about three or four tubers out of 100 that suc¬ 
ceeded, but that he had repeatedly traced the mycelium down the haulm 
along the subterranean branches and into the tubers. 
Potato Sclerotia. —Mr. W. G. Smith had carefully isolated these bodies on a 
slide, and treated them with nitric acid, which destroyed a coat of calcium 
oxalate, and revealed an oval plasmic body exactly as Mr. Wilson has done, 
as reported below. He had found similar bodies with P. Schleideniana in 
Onions and P. nivea in Parsley. Mr. Murray said he had found similar 
bodies in perfectly healthy plants, and suggested that Mr. Wilson should 
repeat his experiments, and that he would test Mr. Wilson’s. Mr. Bennett 
raised the question whether malate of lime might not be present, as malic 
acid was particularly abundant in vegetables. 
The Potato Disease. —A communication was read from Mr. A. Stephen 
Wilson on the so-called sclerotia found in the foliage of Potatoes. After 
referring to the history of them, and to the negative results of Mr. Murray 
and Dr. Flight, who regarded them as calcium oxalate, and not living 
bodies, he considers those observers as acting under a misconception, in 
that they attempted to make a parasite grow in dead matter. Hence Mr. 
Wilson traced the results of “ myceliation ” while the tissue was living, and 
found that the granules of the spherical bodies contained within the coating 
of lime threw up a complete crop of Peronospora in a night’s time. He 
gives a description of his experiments with nitric acid, which, by careful 
application, dissolves the lime but leaves a pellucid ball of granular plasm 
behind. “ This is everywhere permeated by sporeidic granules, some of a 
round form, others of an oblong form, like short pieces of excessively deli¬ 
cate mycelium. The whole has a soft hue, like fine pencilling, and the 
outline is in most places perfectly definitive, with here and there a break, as 
if part of the material has flowed out at the side.” . . . “ A conidium of 
P. infestans is about half the size of one of these bodies, and the contents of 
the conidium are optically very similar to those of the sclerotium as seen 
after being divested of its calcareous coating, and both equally give rise to 
mycelium.” 
The author then gives measurements, and observes that other plasmo- 
diating fungi are coated with lime as some of the Myxomycetes. 
Sparmnnnia and Iloya Boots Clubbing. —Mr. Plowright sent specimens 
which were referred to Mr. Smith and Mr. McLachlan for examination and 
report. 
HARDY PLANTS AT CAMBRIDGE. 
THE BOG GARDEN. 
I CHANCED to call at the Cambridge Botanic Gardens on one of those hot 
sultry days which have made the past summer conspicuous, and having found 
the Curator, Mr. Lynch, under -whose energetic direction the gardens have 
attained such a high state of practical and scientific efficiency, we began to 
examine the many interesting features which are here to be met with. It 
took but a moment’s thought to decide that to visit the plant houses first 
would only add to car discomfort, so we wended our way to the bog garden, 
