Feb. 21st, 1885. 
THE GARDENING WORLD, 
389 
greenhouse form, free - growing and beautifully- 
crested, will doubtless soon be seen on exhibition 
stages. 
Of Onychium auratum (true) there is an immense 
quantity. This for a long time has been very difficult 
to get, but now there need be no difficulty at all, as 
a most successful batch has been raised which are 
now potted off and coming away nicely. Lastrea 
hispida and the beautiful violet scented fragrans are 
also numerous. Nephrodium molle Sangwellii is an 
entirely new and distinct form recently introduced 
from Australia, which will be found very desirable either 
for the fernery or for house decoration. 
Of climbing ferns, the following are to be seen— 
Lygodium microphyllum, volubile, dichotomum 
japonicum, scandens and palmatum. These are 
very pretty trained up wires or pillars, or if allowed to 
twine around a piece of stout string, they may then 
be placed in the summer over places which otherwise 
colour; cool and moisture would appear to be the 
conditions essential to thorough success, and under 
this treatment they grow and retain their fronds much 
better than when during the winter time a dry atmos¬ 
phere is sometimes inflicted upon them through 
the fear of their getting too cold during the night 
time. The lovely Trichomanes reniforme under this 
cool treatment is doing splendidly, the perfect form of 
the fronds proving that the treatment it is receiving 
is the correct one for this interesting species. I have 
many other notes before me, but fear to trespass 
too much on your space. Perhaps on some future 
occasion I may again refresh my memory, enchant 
my vision, and, if possible, interest your numerous 
readers, many of whom I know now look for the 
paper every week to instruct and interest them in 
the many branches pertaining to the gardening pro¬ 
fession. My thanks are also due to the Messrs. 
Birkenhead for their kindness and willingness to 
be accounted for. This was shown by a table giving 
the leaf-area and the diameter of stem of the Horn¬ 
beam, Beech, Elm, Lime, Spanish Chestnut, Ash, 
Walnut, and Horse Chestnut. The size, once deter¬ 
mined, exercised much influence on the form. For 
instance, in the Beech the leaf had an area of about 
three square inches. The distance between the buds 
was about one and a quarter inch, and the leaves lay 
in the general plane of the branch, which bent slightly 
at each internode. The basal half of the leaf fitted 
the swell of the twig, while the upper half followed 
the edge of the leaf above, and the form of the inner 
edge, being thus determined, decided that of the outer 
one also. 
In the Lime the internodes were longer and the leaf 
consequently broader. In the Spanish Chestnut the 
stem was nearly three times as stout as that of the 
Beech, and consequently could carry a larger leaf 
surface. But the distances between the buds were 
ADIANTUM ANEITENSE. 
must be left somewhat bare. Elaphoglossum Her- 
minierii, Meniscium oligophyllum, Niphopsis angus- 
tatus, Niphobolus Heteractis, and Cyrtomium caryo- 
tidium attenuatum, a very distinct form are here in 
healthy specimens. I was exceedingly well pleased 
to meet with a rare and old favourite in Goniophle- 
bium sepultum, and also in the singular fruiting 
form of Anemia villosa. The beautiful Cheilanthes, 
Nothochlfenas, Gymnogrammas and Pellseas, are 
numerous and good, whilst the many distinct forms 
of Selaginellas cannot fail to excite feelings of surprise 
and admiration. Of these latter alba spicata, canali- 
culata, grandis, Victorias, Oregana, and perelegans, are 
distinct and beautiful. 
The large stock of filmy ferns deserves mention, as 
the specimen plants are grown in a north house in 
which no fire-heat has been used for the past three 
or four years, no fear being at all experienced even 
if the thermometer indicates several degrees of frost. 
The smaller plants of Todeas are grown in unheated 
frames outside, the only protection they get on 
severe nights being a mat thrown on the glass. These 
all look wonderfully healthy and are of a splendid 
impart information likely to be of service to growers 
of these beautiful plants.—7 V. Swan, Fallou'field. 
THE FORMS OF LEAVES. 
On the 13th inst. Sir John Lubbock, M.P., delivered 
a lecture on the above subject to a large audience in 
the theatre at the Royal Institution. The lecturer 
said that, greatly as we all appreciated the exquisite 
loveliness of flowers, it must be admitted that the 
beauty of our woods and fields was even more due to 
the marvellous grace and infinite variety of foliage. 
How, he asked, was this inexhaustible richness of 
forms to be accounted for ? Did it result from an 
innate tendency of the leaves in each species to 
assume some particular shape ? Had it been inten¬ 
tionally designed to delight the eyes of man ? or had 
it reference to the structure and organization, the 
wants and requirements of the plant itself ? If we 
considered, first, the size of the leaf, we should find 
that it was regulated mainly with regard to the 
thickness of the stem, and that, when strict propor¬ 
tion was departed from, the difference could generally 
often little greater than those in the Beech. This 
determined the width, and by compelling the leaf to 
lengthen itself led to the peculiar form -which it 
assumed. Moreover, not only did the leaves on a 
single twig admirably fit one another, but they were 
also adapted to the ramification of the twigs, and 
thus availed themselves of the light and air, as we 
could see by the shade they cast without large inter¬ 
spaces or much overlapping. In the Sycamores, 
Maples, and Horse Chestnuts the arrangement was 
altogether different. The shoots were stiff and 
upright, with leaves placed at right angles to the 
plane of the branch, instead of being parallel to it. 
The leaves were in pairs and decussate with one 
another, while the lower ones had long petioles which 
brought them almost to the level of the upper pairs, 
the whole thus forming a beautiful dome. For leaves 
arranged, as in the Beech, the gentle swell at the base 
was admirably suited, but in a crown of leaves such 
as those of the Sycamore, space would be thereby 
wasted, and it was better that they should expand at 
once, as soon as their stalks had carried them free 
from the upper and inner leaves. Hence we saw how 
