340 
THE GARDENING WORLD. 
April IS, 1903 
Gleanings from the World of Science. * 
ROYAL HORTICULTURAL SOCIETY. 
Scientific Committee. March 10th. 
Present: Dr. M. T. Masters (in the chair); Messrs. Worsley, 
Odell, Yeitch, Nicholson. Shea, Brown, Saunders, Massee, 
Douglas, Michael, Bowles, and Elwes, Dr. Rendle, Revs. W. 
Wilks, and G. Henslow, hon. secretaries. Visitor, Mr. de Barri 
Crawshay. 
Scientific Investigations. —Dr. Masters laid a resolution 
before the committee, observing that the question of the society 
undertaking in its gardens to investigate pixysiological and other 
matters bearing upon horticulture was a most pressing one, to 
be carried out under a properly appointed director. After 
several suggestions were made by Mr. Elwes, Mr. Massee, Mr. 
Brown, and others, the resolution was seconded by Mr. Shea, 
and passed unanimously. 
Pelakgonittm Disease. —I)r. Cooke reported as follows upon 
the leaves sent by Mr. Meredith, Tibberton, Newport, Salop : — 
“ Two leaves of Pelargonium submitted were spotted indistinctly, 
and in one instance with an appearance of rotting, as caused by 
the pot moulds. It is reported that the disease appears on this 
variety only ‘ like blisters on the young stem and cracks on the 
older wood; the leaves are attacked by these spots, which soon 
cause them to wither.’ The leaves sent were closely crushed and 
compressed, so that all trace of any delicate mould, if present, 
would have been destroyed. Examination of the spots under the 
microscope exhibited no trace of mycelium, or spores ; stems not 
seen. From the specimens sent no evidence can be found of 
fungus parasite, otherwise the appearance would suggest the 
attacks of a Peronospora, of which one species is known in 
Germany and Belgium to attack wild species of Geranium. Pos¬ 
sibly it might prove to be the early stage of one of the white 
moulds, such as Ramularia, but it has not the appearance of 
Ramularia Geranii. At any rate, the leaves sent 'afford no evi¬ 
dence from which to determine the disease.” 
Copper in Soil. —With regard to the specimens of soil sent by 
Mr. A. Gaut, Yorkshire Col., Leeds, in which some fruit frees 
grew, “ the leaves of which were annually of a golden colour,” 
Dr. Voelcker reported as follows :—“ Both the top 'and sub-soil 
contain distinctly material amounts of copper; the top-soil ’046, 
and the sub-soil "265 per cent, of copper oxide (CuO). Further, 
I ascertained that the copper is in the insoluble condition. 
There is no copper removable in a water solution in the ordinary 
way.” 
Calanthes and Mendel’s Law. —Mr. Chapman forwarded the 
following reply to Captain Hurst’s observations reported at the 
last meeting :—“ I am not at all surprised to find Captain Hurst 
claiming the fact of C. OakwoOd Ruby and C. Sibyl having been 
derived from the same seed pod, and bearing directly on the 
action of Mendel’s law. Had the rose or rose-carmine character¬ 
istics been maintained, Captain Hurst might have been sure of 
my support of the principles of which he is such an able ad¬ 
vocate. Let us see what has really taken place. The first 
cross-producing C. Veitchi from C. vistita and C. (Limatodes) 
rosea ; the second cross was between C. + Veitchi and C. vestita 
rubro-oculata (giving a second cross with C. vestita) produced 
C. Coobsoni, with a yellow eye or disc, also C. Alexandri. Here 
the first change takes place. The deep ruby eye as seen in C. 
vestita rubro oculata is removed to the front lobe of the lip’, and 
each of the petals, the sepals only being white, in some cases 
slightly tinted with the colour of the petals. It is remarkable to 
note that the rose or rose-carmine colours have disappeared. I 
cannot get at the exact parent 'that was used in the next genera¬ 
tion, but from the information I can gather, the darkest varieties 
were selected and crossed with each other, until the remarkable 
variation between C. Sibyl and C. Oakwood ruby was produced. 
In the latter case the flower of C. vestita rulbro-oculata had been 
turned ^inside out. I cannot trace any of the rose or rose-carmine 
9^ G y or . ^ le shape of Limatodes in the flower as seen in 
G Veitchi, but in the bulb the shape and general structure re¬ 
sembles C. (Limatodes) rosea, I cannot see what advantage can 
be procured by intercrossing 0. Oakwood ruby with C. Oakwood 
ruby. I cannot expect to gain more from this than I procured 
nearly six years ago when crossing C. Veitchi with its own pollen, 
and the result was that it reproduced itself from seed. I might 
add to this another instance in which I procured a primary 
crossed hybrid from seed. Nearly ten years ago I crossed C. 
leeanum (a very fine form of it), and the result brought its 
parent, with no more variation than constitutional or cultural 
conditions are capable of bringing about. With such clear re¬ 
sults as these I, at least, cannot see where the application of 
Mendel s law applies, ” 
Larch Trees. —Mr. Elwes observed that one subject which 
especially might be investigated as being most important for 
forestry was the diseases of Larches. It was said that the spores 
of Peziza enter the wounds made by chermes, and that it appeared 
some trees are more or less able to resist the chermes. Hence, 
if such a race could b'e established it would greatly assist cul¬ 
tivators, who might be able to grow valuable trees of this kind. 
Trees in Park Lane. —Mr. Saunders showed photos of some 
trees the trunks of which exhibited a knotted appearance. Mr. 
Elwes observed that Oaks frequently showed the same feature 
up to ten or more feet in height. The general opinion was that 
it was the result of numerous embryo buds in consequence of 
severe pruning, and that there was no fungus causing it, though 
similar excrescences often result from insect punctures. ° 
Placea lutea. —Mr. Worsley showed germinating seeds of 
this plant, and described how the radicular end of the embryo 
first rises upwards and then turns downwards, producing a (pro¬ 
bably temporary) axial root. The cotyledon rises in a loop, like 
that of an Onion, the tip being retained in the endosperon till 
it is exhausted. Mr. Elwes noted that the seeds would only 
germinate after such a time as an adult plant would throw up 
its foliage. 
Hymenocallis Hybrid. —He also showed flowers of a hybrid 
vittatum and H. sub-barbatum, the red colour of the male being 
replaced by pink in the hybrid. He observed that this illus¬ 
trated the prepotency of the “ erraticism ” of the female parent, 
in that the offspring bore “ red tips and feathering ” of the 
female, instead of being strictly intermediate in character. 
Hymenocallis Hybrid. —He also showed flowers of a hybrid 
between H. angusta (female) and H. moritziana (male), in which 
the flowers agreed with the former and the foliage with the 
latter. A curious feature was a correlation between an increase 
in the number of ovules and the flower having more perianth 
leaves than normally. 
Euonymus and Caterpillars.— Mr. Carter, 22, Pelham 
Crescent, inquired as to the best method of dealing with the 
caterpillar which attacks the Euonymus. Mr. Saunders replied 
as follows : —“ The caterpillars on Euonymus are those of the 
' Magpie ’ or ‘ Gooseberry and Currant Moth ’ (Abraxas grossu- 
lariata), a very common insect which may often be seen flutter¬ 
ing about during the daytime—it flies very badly; the general 
colour of the insect is creamy white, ornamented with black 
spots ; but they vary very much in colour, some nearly white 
specimens having been found, and others which were almost 
black. The insect measures lgin. to lfin. across the open wings. 
Ihe chrysalides are not made in the ground, but in dead leaves, 
which they spin together, or in some similar kind of shelter. 
Any leaves which do not fall with the others should always be 
examined, as it will be often found that the caterpillar has spun 
the edges together and attached it to the bush, and has under¬ 
gone its transformations within it. Picking the caterpillars 
off by hand is no doubt one of the most effectual ways of dealing 
with this insect, but it is tedious ; spraying the bushes with a 
solution of paraffin emulsion would probably kill a large 
number. In the winter all the dead leaves beneath the bushes 
should be collected and burnt. The moths may be caught very 
easily in a butterfly net.” Mr. Druery observed that he had 
tried dusting with Hellebore powder freely into the web- 
colonies, and that it was effectual in destroying them. 
Reversion in Hybrids. —Mr. de B. Crawshay instanced a case 
of reversion in Odontoglossum crispum x 0. c. crawshayanum. 
The flowers were crossed in 1895, sown in 1896, and bloomed 
in 1903. ^ He added the following remarks :—“A seedling raised 
.upon a fine Odontoglossum crispum ? crossed by O. c. craw¬ 
shayanum $ which has blotches on the sepals and petals fin. 
long, of deep purple brown. The seedling has no blotch or 
spot save three extremely small ones in two of the four lips 
(four blooms). Absolute 'reversion has occurred both in form 
and absence of blotch. The form is as bad as can be. Hence I 
deduce that my contention of years’ standing, that a true 
crispum is white and unspotted, has been proved by the first 
plant to bloom, which has reverted beyond all possible expecta¬ 
tion. The blotching of a so-called spotted crispum is, I con¬ 
tend, the remains of hybridity. This, I consider, is in some way 
of Nature s own acquired from O. luteo-pupureum ; and as 
these blotches are therefore adventitious, they fail to transmit 
their characters to the resulting progeny— ergo, the spotted 
crispums are not pure crispums at all, but hybrids or crosses. 
(See my article upon ‘Reversion in Odontoglossum’ in 1 G. C.,’ 
14j 03.) 
