156 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ August 22, 1S8P. 
the proper time, and ventilation given after the house has become 
highly heated, there is a vast divergency of power that may cause good 
or bad effect. 
Granted that ventilation in some form or other is indispensable to a 
healthy condition of the plants raised in glass structures, it should 
follow that it is the faulty manipulation of the ventilators that causes 
the mischief rather than the non-observance of the principles that cause 
the adoption of such proceedings, especially if the views of such as 
advocate a close system of cultivation is taken into account, for if, as 
they affirm, scorching is an evil almost unknown to such as thoroughly 
understand the practice of non-ventilation, the question turns upon the 
importance of a complete knowledge of the reason why we ventilate 
and why we do not. Some cultivators assume that the chief motive 
should be with the object of admitting fresh air, and on every possible 
occasion when they deem it favourable proceed to ventilate their fruit 
or plant houses with a zeal that should assure astounding results if that 
alone were the chief factor of success. I consider it waste of energy to 
strive to attain such a fine adjustment of temperatures. If once those 
in charge of glass houses can be induced to comprehend the principle 
on which ventilation is practised, there remains but little necessity to 
endeavour to instil the minute details. If a young beginner can once 
grasp the ideas that an abrupt change in plant life, whether it be in 
respect to air, earth, or water, little remains except occasional unavoid¬ 
able accidents and such like contingencies to insure the successful and 
satisfactory issue to such a practitioner’s efforts. 
Now the question presented is, Why do the phenomena of scorch¬ 
ing occur in properly ventilated houses and seldom or never in those 
where no ventilation is afforded ? This no doubt is somewhat puzzling 
to such as endeavour to impress on the uninitiated the disastrous effects 
in neglecting to ventilate their houses at the prescribed proper moment. 
I have never been fortunate enough to obtain the precise views of such 
a one on the state he would expect the occupants of a house to present 
after a spell of non-ventilation. When shading is practised either by 
blinds or by means of lime or colour washes a twofold end is gained— 
the fierce direct rays of the sun are intercepted and broken up, which 
reduces their heating power, and at the same time obviates the necessity 
of opening the ventilators to prevent the temperature being raised too 
high ; this again favours the maintenance of a more steady and genial 
atmosphere, and in such atmosphere where humidity is preserved to be 
plainly, perceptible to the senses, no scorching can occur if the 
diagnosis is correct that I have given previously. So that it appears 
that scorching is not a question of ventilating, but of the adequate 
supply of moisture in the air within the structure, and I might also add 
to the roots of plants as well. Some severe cases of leaf-scorching that 
have come under my notice have been plainly attributable to this cause, 
and when such is the origin of the mischief shading and close ventila¬ 
tion, with free disposition of moisture atmospherically will only tem¬ 
porarily allay the evil, as it cannot fail to occur on the first occasion 
that the plant is subjected to anything approaching an evaporating 
influence. 
Another phase of the injury that owes its origin to defective glass is 
sometimes met,.but not frequently, as the cause is generally promptly 
removed when it is observed that plants placed in a certain position in 
the house are invariably injured if allowed to remain there for any 
length of time. This is undoubtedly caused by the globular unevenness 
of the glass focussing the rays of the sun, so that they blaze with con¬ 
centrated energy upon certain parts of the plants, and literally burn 
them. Much the same effect is produced—generally during the early 
part of the season—upon the common Laurel, Holly, and other smooth 
surfaced leaves. Small circular holes being produced in this case, re¬ 
sulting from moisture being deposited on them by a slight shower that 
is not sufficient to moisten the whole leaf, this causes the deposit to 
assume a tiny globular form, which acting as a lens when the sun 
again shines cause the death of that portion of the leaf. It is, I 
imagine, from this fact that the popular idea has gained ground that 
watering plants over the foliage during bright sunshine will cause 
disastrous results.—M. Coombe. 
THE ROYAL HORTICULTURAL SOCIETY’S JOURNAL. 
The second part of vol. xi. of the above Society’s Journal, edited by 
D. Morris, Esq., M.A., and the Rev. W. Wilks, M.A., Treasurer and Secre¬ 
tary respectively, has just been issued from the offices, 117, Victoria Street, 
S.W ., and though it has been long expected the important character of 
its contents will compensate in a great measure for the unavoidable 
delay that has occurred. The part contains 138 pages, and includes the 
papers read with the consequent discussion at the meetings of the 
Society from March 12th to June 11th of the present year; but does 
not comprise any reference to the meetings of the Fruit, Floral, and 
Scientific Committees during the same period, this probably bein°‘ re¬ 
served for the next issue. It is published at the price of 5s. to ^on- 
I ellows,. which in these days of cheap literature might be regarded 
as exorbitant by any purchaser who had not previously seen the°work. 
A brief glance at the leading papers will show, however, that they are 
interesting alike to amateur and professional horticulturists. 
SAXIFRAGES. 
The first paper is one by Mr. J. G. Baker, entitled “Notes on 
Saxifrages, in which he deals with their geographical distribution and 
the principal characters of the genus. Referring to garden Saxifrages 
he says :— 
“ Out of the 180 species we have just about half in cultivation. There 
are a great many names in the garden catalogues of which botany 
knows nothing. As this paper will be printed in the proceedings of our 
Society I thought the best thing I could do would be to give a classified 
catalogue of the cultivated species, with their names and native coun¬ 
tries. I have followed Engler’s classification and adopted his numbers, 
so that the blanks will show roughly where the non-cultivated species 
fall. The great bulk of the cultivated species come under six out of 
the sixteen groups. Three out of these six have the cotyledons tipped 
and the leaves more or less bordered with glands, and the three others 
are without them. Of the non-foveolate groups Dactyloides includes 
twenty-one species. These are marked by their mossy habit, copious 
trailing leafy shoots, palmately divided leaves, and few corymbose 
flowers, with petals usually large and white. The best known species of 
this group are hypnoides, ceratophylla, and emspitosa, with its 
numerous varieties. Two fine large flowered types of recent introduc¬ 
tion are Camposii and Maweana. The second non-foveolate group is 
Robertsonia, which only includes three species, umbrosa, Geum, and 
cuneifolia. The third is Bergenia (called Megasoea by Haworth), which 
is confined to the Western Himalayas and mountains of Siberia, and is 
very clearly separated from all the other groups by its red unspotted 
petals, thick rootstocks, and large undivided leaves of firm texture. Of 
the foveolate groups the best known is Euaizoonia (or crustaceous 
Saxifrages), in which the densely rosulate leaves are margined with 
numerous chalk-secreting pores, and the numerous flowers form ample 
erect panicles. The most widely spread species of this group is 
S. Aizoon. For purposes of cultivation, Cotyledon, florulenta, longi- 
folia, and lingulata are the finest. Several of the species have a re¬ 
stricted range amongst the mountains of Southern Europe. I should 
like to know how far these need carbonate of lime for their successful 
cultivation. In Kabschia, under which eighteen cultivated species fall 
(of which we may take S. Burseriana as a type), the leaf-glands are 
much fewer and less conspicuous, the flowers fewer, and the leafy shoots 
last for some years, and are thickly beset down below the fresh leaves 
with the relics of the old ones. In Porphyrion, which includes 
oppositifolia and three other high alpine species, the leaves are opposite 
and decussate, and the red or purple flowers solitary on short leafy 
peduncles. In the small Chinese and Japanese group Diptera there are 
long creeping stolons, and the spotted petals are very unequal in size. 
The Californian S. peltata has large peltate leaves like that of a 
Rhubarb or Gunnera. I do not think there are many species not yet 
introduced that are worth much from a garden point of view. Out of 
the thirty-five Himalayan species, which are mostly endemic, twenty- 
six have not yet been introduced.” 
The paper is concluded with a list of species (166) and hybrids with 
their parentage (II). 
Mr. George Paul followed with a paper on the cultivation of Saxi¬ 
frages, in which some useful practical hints were condensed into small 
compass. Noting the Encrusted species he remarked :— 
“ One of the most interesting sections of this family is that known as 
the Encrusted Saxifrages. In this the leaves are of a tufted habit, 
jewelled, so to speak, with silvery dots (of carbonate of lime), so that 
even when not in flower they are beautiful objects. I have found these 
thrive best under culture, either in pots placed in a sunny open place, 
or planted on rocky buttresses standing out from the face of the rock- 
work. These buttresses may be formed of rocky debris of limestone or 
granite (the plants appear to thrive equally well on either), but it is 
necessary that the roots should be able to penetrate to a good depth. 
Others may be planted in situations fully exposed to the sun on the 
sides or upper surfaces amongst broken stones ; whilst the beautiful 
S. longifolia of the Pyrenees prefers to be planted vertically between 
stones, and for choice looking towards the west. Other sorts in this 
section, such as S. Aizoon and varieties, S. lanfoscana, S. pyramidalis, 
will thrive anywhere on rocky walls ; whilst a special few, such as the 
beautiful S. Burseriana and S. cassia, always impatient of moisture, need 
the highest and best drained situations that can be given them. Once 
established in such situations, plants of this section form dense tufts of 
silvery foliage often from 6 inches to 1 foot in diameter. They bloom 
abundantly during the months of April, May, and June, the flowers 
being mostly white, but sometimes, as in S. Macnabiana, with carmine 
or red spots on the petals. Success in the culture of these plants depends 
on the use of gritty or sandy soil, on good drainage, an open sunny 
aspect, and plenty of water in summer whilst the plants are in a grow¬ 
ing state.” 
Cultural notes on the principal groups and species of Saxifraga are 
also contributed by Mr. G. Reuthe of Tottenham. 
HYACINTHS. 
Three papers are devoted to Hyacinths. One by Heer A. E. 
Baarnart, Haarlem entitled, “ Historical Notes on Dutch Hyacinths ” 
reviews the earlier history of those plants briefly but thoroughly. A 
second paper by Heer J. H. Kersten, Haarlem, discusses the cultivation 
of Hyacinths in Holland, in which we are informed that 670 English 
acres are occupied with these plants in Holland, and at least 5000 men 
are engaged in the trade. It is also said that:— 
“ The flowers, having no value in Holland, are often sent to the 
English market. This, however, is considered so injurious to the trade 
