April 13, 1889. 
THE GARDENING WORLD. 
515 
taking two branches of each sort, stripping one branch 
of its leaves, and placing the lot in different vessels of 
water. The branches with leaves on them imbibed in 
twelve hours of the day 15 ozs. to 30 ozs., according to 
the number of leaves on them, and weighed lighter ; 
while those without leaves imbibed but 1 oz., and were 
heavier in the evening than in the morning, they 
having transpired little. 
It has also been observed that a surface which, in 
calm weather, would give off 100 parts of moisture, 
would give off 125 in a moderate breeze, and 150 in a 
high wind ; hence the benefit of protection to fruit and 
other garden crops by high walls protecting trees, &c. 
-“>X<—- 
THE FERNERY. 
Wardian Cases. 
Many are disappointed with the comparatively short 
duration of Ferns, particularly Adiantums in dwelling- 
houses. Some of the more leathery-leaved kinds, it is 
true, will endure the dry atmosphere of a dwelling- 
room all the year round, provided they are grown in a 
window, or are otherwise properly exposed to light. A 
great number of the most delicately-cut and beautiful 
Ferns, both British and exotic, can be successfully 
grown, however, in Wardian cases, which are simply 
small, close-fitting, and almost air-tight greenhouses, 
named after Mr. H. Ward, who first invented them. 
These cases can be made of any convenient shape or 
size, to suit the convenience of a would-be owner, 
according to the size of his windows, whether bay or 
otherwise. Larger cases may be stood on tables placed 
close to a window or other sufficiently-lighted places, 
such as halls or porches, or even on balconies—as, for 
instance, in town residences. Some of the finest col¬ 
lections of filmy Ferns have been grown even on the 
tops of those establishments. Such structures are 
generally made in the form of small span-roofed green¬ 
houses, and are elegantly and lightly built, so that their 
presence in dwelling-houses is neither unsightly nor 
objectionable. The bottom of the cases must be water¬ 
tight to prevent injury to the windows or tables on 
which they are stood. Large ones should have a special 
means of drainage, and the superfluous water carried 
away by means of a pipe. The smaller ones are so 
close that little water is required from one year’s end to 
the other, after the first good soaking. 
In the bottom of the case should be placed a good 
layer of broken pot-sherds or brick rubble to act as 
drainage. Over this lay some moss, then a mixture of 
peat, a small quantity of loam, and, some sand. The 
centre of the case can be built up in the form of a 
miniature rockery, of any suitable design, according to 
the fancy of the owner, using any soft or porous stone 
in quantity, and, if considered desirable, pieces of a 
more ornamental character, whether porous or otherwise. 
White quartz is generally much appreciated for this 
purpose when procurable. 
Having got everything ready, the next thing is to 
set about planting the Ferns, which may be of a rich 
and varied character ; but the species used should 
always bear some proportion in their relative size to 
that of the cases in which they are planted. Tall- 
growing species would soon monopolise the whole case, 
a state of matters by no means to be desired. Provided 
always that sufficient space is allowed each species to 
develop its natural proportions, then the greater 
number of kinds that can be accommodated, the greater 
interest attaches to their cultivation. Very little at¬ 
tention is required after the first planting, except the 
replacing of any dead ones by fresh specimens and the 
cutting away of dead fronds. To facilitate these 
operations one of the top squares of glass should be 
moveable. 
A collection for a Wardian case may consist largely 
of the smaller and more ornamental British Ferns, such 
as Adiantum Capillus-Veneris, Asplenium fontanum, 
A. lanceolatum, A. Trichomanes and its crested 
variety, A. viride, any of the filmy Ferns, as well as 
the Bladder Ferns (Cystopteris fragilis, C. regia), and 
others. The Sea Spleenwort (Asplenium marinum), 
which on some rocky sea-coast places may be found in 
thousands lining the seams and crevices of the rocks, is 
admirably adapted for planting in Fern cases, where it 
obtains a luxuriance unknown in a wild state. If 
exotic kinds are preferred, then what could be more 
appropriate than Adiantum cuneatum, A. c. gracile, or 
Asplenium viviparum with its slenderly divided fronds 
bearing little plantlets all over it? Doryopteris palmata 
is a small-growing and bold kind of distinct character. 
Many kinds can be used in a small or seedling state, 
and renewed annually if they get too large. Several of 
the Selaginellas may also with profit be used. 
otes from Scotland. 
Scottish Horticultural Association. — At 
the opening meeting of the thirteenth session of this 
association on the 2nd inst., Professor Bayley Balfour, 
on taking the chair as president for the ensuing year, 
began his inaugural address by thanking the members 
for his election. Having pointed briefly to the 
practical character of the work of horticulturists, he 
said he represented more the laboratory side of botany, 
and he felt that, in honouring him by asking him to 
preside at their meetings, they recognised that there 
was no antagonism betwixt the botanical side and the 
horticultural—that workers in both fields were necessary 
in order to have real progress in science. For his 
introductory address he had chosen the subject of 
“ Variation in Plants,” which was of the most profound 
interest to horticulturists. The chief reason why he 
had taken up this topic was that he wanted to bring 
before them a question which was the most discussed 
in the scientific world at the present day amongst 
biologists—Are acquired characters transmissible from 
one generation to another ? A new view had arisen on 
the subject, advanced by Professor Weissman, Germany, 
to the effect that in order to have variation the only 
way in which it could be effected was by means of 
sexual intercourse ; but he (the president) asked, if it 
was only by this means that they had got this power 
of variation at the present day, how was there ever any 
power of variation at all ? Having suggested the 
carrying out of experiments with the view of arriving 
at some definite conclusion on the point, he said the 
question was one which was awaiting settlement, and 
one which appealed, he thought, very directly to the 
members of the association, because they had it in their 
power to make so many observations in connection 
with variation. It was a question of very great im¬ 
portance to know if there was any evidence that these 
acquired habits were or were not transmissible. He 
was strongly inclined to think they would eventually 
get evidence in favour of the transmission of acquired 
characters and habits, but at present if they ask him to 
point to a single instance where he could show without 
any doubt that acquired characters were transmissible, 
he confessed he was unable to do so. In closing, he 
expressed his thanks to the association for the leading 
part they took in the agitation which was started last 
summer in connection with the preservation of the 
Eoyal Botanic Garden for the people of Scotland and 
the people of Edinburgh. He was anxious that the 
Botanic Garden should be made something more than 
a mere place for the exhibition of plants. He should 
like to have it as far as possible a place for real 
horticultural training. On the motion of Mr. John 
Methven, seconded by Mr. Alexander Milne, the 
president was heartily thanked for his address. A 
number of awards were made to assistant gardeners for 
essays prepared by them. None of the productions, it 
was stated, could be said to be of more than average 
merit. 
North of Scotland Horticultural Asso¬ 
ciation. —Tree-growing in Towns. —The monthly 
meeting of the members of this association was held in 
the Christian Institute, Aberdeen, on Wednesday 
evening, 3rd inst. There was a good attendance, and 
Mr. James Walker occupied the chair. The first 
business on the card was an interesting and instructive 
paper by Mr. Robert Walker, gardener, Victoria Public 
Park, Aberdeen, entitled, “Trees most suitable for 
growing in Towns.” Mr. WAlker said it was a popular 
but erroneous notion, that trees would not thrive in the 
streets of smoky towns. People often saw in France 
streets bordered with rows of handsome young trees, 
and they naturally compare these verdant avenues with 
our own streets, where trees were rarely planted, and 
come to the conclusion that (there was “something in 
the air,” which prevented trees thriving in even an 
ordinary packed city. Consequently they contented 
themselves with pretty little gardens. These were 
excellent in their way, but they effected only a partial 
good. The slight good effected by fine parks placed 
here and there in or towards the outskirts of a city was 
as nothing compared with what might be carried out 
by so planning and planting streets and roads, that the 
air might be comparatively pure and free, and the eye 
refreshed with green at almost every point. 
It had been said that the streets in most European 
cities were far too narrow to admit of tree planting. 
This was not the case. When trees were planted in 
close lines to form a shady avenue, their natural ten¬ 
dency was to make a beautiful and picturesque arch. 
After referring to the additional value that would be 
given to property by the planting of trees in streets, 
and to the importance of the scheme from a sanitary 
point of view, Mr. Walker proceeded to describe the 
kind of trees most suitable for street planting. The 
best of all trees for European cities was the Western 
Plane, which might be seen in many towns from the 
heart of London to the shores of the lakes of northern 
Italy, and numerous places thousands of miles from its 
native, home. It was by far the noblest city tree, and 
nowhere were there finer individual specimens to be 
seen than in London. There were the common Syca¬ 
more, the purple-leaved Sycamore, and the rose Acacia, 
all specially suitable. Numerous other trees were 
mentioned, such as the Poplar-leaved Birch, the pyra¬ 
midal variety of the Oak, and the new American broad¬ 
leaved Lime, all of which had particular qualities to 
recommend them for streets and avenues. The Haw¬ 
thorn family generally furnished a greater number of 
hardy ornamental dwarf trees than any other known 
variety. They were not only pretty and fragrant, but 
the aspect of the fruit in autumn borne in showers of 
bright red, yellow, black and scarlet was of itself a 
recommendation which should entitle these trees to 
general cultivation. 
The extensive use of Lime, Lombardy Poplar, Horse 
Chestnut, and Beech trees in towns was a great mistake. 
At the end of July the Limes were often the most 
miserable-looking trees that could be seen, and that in 
the midst of summer. The writer then treated of the 
soils most suitable for trees of the kinds he had 
suggested. As to the planting of the trees, it was a 
fatal mistake to plant them in squares ; they would 
thrive far better in rows. The special features of each 
class of trees were then dealt with, interesting in¬ 
formation being given regarding their suitability for 
streets, villa fronts, &c., and the treatment they should 
receive. A large selection of trees suitable for smoky 
streets and suburban roads was then given, and, in 
conclusion, Mr. Walker said they should have ample 
room and thorough exposure. They should not, as it 
often happens, be made to acquire heights at the 
expense of stoutness by over-crowding. They should 
have straight, stout, clean stems, with handsomely 
furnished, well-balanced heads, and from being fre¬ 
quently transplanted, should be splendidly rooted. 
They should be, without doubt, the finest trees 
possible to be had for purposes of strtet planting. The 
girth of the stems should be taken at 4 ft. from the 
ground, and not at the base, which is often deceptive. 
This would give a true indication of the sturdy 
character of the trees. 
Discussion was then invited by the chairman, and 
after Mr. Taylor, Clashfarquhar, and Mr. France had 
made a few remarks, Professor Matthew^ Hay, Aberdeen 
University, said he agreed as to the possibility of 
utilising the planting of trees in cities. Of course, it 
might be that in other climes—hotter climes than our 
own —there were certain advantages to be obtained 
which did not come to us, such as screening persons 
from the hot sun. That advantage was one of con¬ 
siderable importance, but it was not the only one. 
There were many others, and one was the advantage from 
an festhetical standpoint—the beautifying of the streets. 
He thought they must all feel that one of the greatest 
wants in our streets was something natural to rest the 
eye on. There was nothing green in our streets on 
which the eye could rest, and a little bit of nature 
would be very pleasing and refreshing. Something had 
been said about the advantages from a sanitary stand¬ 
point, and he certainly felt that trees in the streets 
would be a decided advantage to any city in that way. 
Trees, chiefly of the Blue Gum species, had been planted 
in the Campagna at Rome, for the purpose of getting 
rid of the malarial germs, and they seemed to have 
served the purpose very well. He did not know that 
trees were required in this country for such a purpose, 
but no doubt they would exercise a good sanitary in¬ 
fluence by purifying the atmosphere, by diminishing 
the amount of carbonic acid, and increasing the amount 
of oxygen—playing an opposite part to human beings. 
He dared say that he had shared the erroneous popular 
belief that trees did not grow very well in the middle 
of a city ; but such an idea had been completely dis¬ 
pelled, for he saw that it only required that it should 
be known what was the right kind of tree to plant, and 
what was the proper treatment for it. He considered 
they were very much indebted to Mr. Walker for his 
admirable paper. 
Several other members took part in the discussion, 
and a suggestion was made that the paper should be 
printed. °At the close a hearty vote of thanks was 
accorded to Mr. Walker for his admirable paper. The 
next business was a paper by Mr. Taylor, Clashfarquhar, 
on artificial and natural soils. Mr. Taylor explained 
that in the short time which was at their disposal he 
could not do justice to the subject; but he gave an 
idea of the lines he was to proceed on, so that members 
might be prepared to discuss the matter fully when it 
came up again. 
