662 
THE GARDENING WORLD. 1 A» g „.i 19 , 1905. 
a number of the elite were grown under glass 
with charming effect. The great beauty of all 
the varieties shown and the extraordinary 
extent to which a specifically simple form may 
be transformed into a finely dissected type of 
utterly different appearance were well evi¬ 
denced, the variation being often far greater 
than is seen between quite different species. 
The fact, too, that these wild sports transmit 
their peculiarities as a rule truly to their pro¬ 
geny by spores was also adduced as strengthen¬ 
ing Prof. Hugo de Vries’ Theory of Mutation, 
by which he claims that such sports in plants 
generally have probably played an important 
role in the evolution of species. All that is 
needed, indeed, is a capacity in such a sport to 
establish itself freely to constitute it a species 
proper, since otherwise it fulfils every definition 
that can be formed of what a, species really is : 
a species is merely a constant distinct variety 
of a genus, which breeds true to type, and 
many of the wild sports fulfil these conditions 
perfectly, and are, as has been stated, even 
more distinct from the normal than many 
species are from each other. 
Supplementary Replies 
BY OUR READERS 
To Answers in the “ G. W.” Enquire Within. 
Blue Hydrangeas. 
These remarks regarding “ N. P.. Hants’ ” 
query on Hydrangea flowers, pink and blue, I 
am well acquainted with. I have a plant 
from which I never fail to procure flowers of 
the deepest blue. This plant neither grows in 
peaty soil, shady situation, nor gets any arti¬ 
ficial waterings. In this instance the cause 
of it may rightly be attributed to the presence 
of iron in the soil. The gardener who- was 
once in charge told me of his experiment with 
it. I cannot bear in mind exactly the direc¬ 
tions he gave or the compost used for the 
purpose, but one thing he used was iron peel¬ 
ings from the blacksmith’s anvil. This plant 
is quite a picture during its flowering season. 
It is about 4 ft. high, and as much through, 
and grows in a very sunny situation. I ob¬ 
tained some cuttings from it last year to see if 
the colour was quite naturalised in it, but, to 
my disappointment, they have all turned out 
pink. Perhaps these few remarks will help 
others to give it a trial, especially those re¬ 
quiring blue forms. I will endeavour to get 
any other information possible that will tend 
to the colouring from the experiments at a 
future date, if room can be found for it in 
this column. I will also procure a few flowers 
for the Editor’s inspection, should he be 
pleased with them. Hydra. 
[Please do.—E d.] 
Books of Designs. 
Observing the correspondence in The 
Gardening Would, July 29tli, about “ Books 
of Designs for the Flower Garden,” I beg to 
state that John Lane (Vigo Street, London) 
publishes several books on garden designs 
The following are three published by him : — 
(1) “Garden Craft, Old and New,” by John 
D. Sedding, with nine full-page illustrations, 
price 7s. 6d. net ; (2) “ The Ethics of Garden 
Design,” by Thomas H. Mawson (author of 
“ The Art and Craft of Garden Making ”), 
with numerous illustrations, and thirty 
specially-drawn plans, price 10s. 6d. net. 
Another is Volume XXV. of “ Handbooks of 
Practical Gardening ” (all charming books), 
“ The Book of Garden Design,” by Charles 
Thonger, illustrated, price 3s. 6d. net. John 
Lane will send to anyone his little booklet, 
with full descriptions of books tor and about 
gardens, on receipt of a post-card, post free. 
Hilda Brickwood. 
Pink and Blue Hydrangea Flowers. 
It seems very strange, considering the 
length of time this peculiarity ha® been 
noticed, that our scientific men have not dis¬ 
covered the cause of it. I well remember 
seeing big bushes of Hydrangea hortensis one 
mass of blue when visiting some Cornish 
gardens a few years ago. There the cause is 
generally attributed to 1 the large quantity of 
iron in the soil. I would suggest that, for 
the benefit of the profession, wherever blue 
flowers show themselves, the gardener should 
have the soil analysed, at the same time 
making a note of the surroundings. It often 
may be noticed one garden may invariably 
have a fair percentage of blue flowering 
Hydrangeas, while the adjoining one always 
produces those of a pink colour 1 . Again, the 
occurrence may be confined to a county. 
Being bounded on two sides by the sea, may 
account tor it being met with in Cornwall. 
But proximity L> the sea is evidently not an 
essential condition, for blue flowering 
Hydrangeas are, I believe, met with in Shrop¬ 
shire and Worcestershire, and still further 
inland. It would be of service to- know if it 
is of common occurrence in “ W. P.’s” 
locality. It would be very interesting to find 
how often and how near such happens to 
London. A. J. 
[At Coombe Wood and Coombe generally. 
—Ed.] 
Sources of Plant Food. 
Perhaps the Editor will permit me to add 
to his reply to “ H. A. L.,” on page 632 of 
“ G. W.,” by stating that plants only take up 
their food in the form of gas, water, and salts. 
A certain amount of these are obtained from 
the atmosphere through the medium of leaves 
or foliage, but the mineral elements of plant 
food are abstracted from the soil through the 
roots. When manure is added to the soil, 
the decomposition of the manure produces 
various gases, etc., while the action of the 
manure on the soil may be said to cause a 
disintegration of the soil itself, setting free 
mineral elements, which are also valuable as 
food, and this process of decomposition and disu 
integration goes car until manure is decom¬ 
posed. The fertility of the soil is maintained or 
increased by annual dressings of manure, as 
the residue ten Is to replace the soil which 
has been assimilated or removed by the pre¬ 
vious crop. Plants feed indirectly upon the 
soil, but certain elements must be present in 
the -soil in some degree in order to transform 
the soil into the food suitable to< the plant’s 
needs. Manure partly effects this trans¬ 
formation, and the fundamental principle of 
economical manuring consists in studying the 
needs of individual crops, and supplying to 
the soil, through the agency of manure, those 
constituents which that particular crop is 
known to require, or which it is known the 
soil is deficient in. G. F. 
A Handsome Chinese Plant. 
(Rodgersia pinnata.) 
China has given us another remarkably 
fine thing in Rodgersia pinnata, a plant of 
noble aspect and exquisitely beautiful in 
leaf and flower. The hardy plantsmen 
among our readers will be acquainted with 
the older but very handsome R. podophylla, 
with its richly-tinted foliage and tall panicles 
of cream-coloured flowers, but we are bound 
to give pride of place to the new-comer, for 
it is superior in every detail. Its foliage is 
even more handsome, being possessed of a 
richer and more lustrous bronze shading, 
while the flowers are of a lovely rosy hue, 
with a slight admixture of yellowish cream, 
just sufficing to show up the brighter tint to 
fullest advantage. One generally associates 
the Rodgersias with the bog garden, but it is 
doubtful whether they are happiest there ; 
indeed, we have found that unless the crowns 
of the plants are sbghtly elevated so as to 
be clear of water in winter losses are almost 
inevitable, for although the roots delight in 
an abundance of moisture during the grow¬ 
ing season, the crowns quickly rot if too 
wet in winter. We believe a position on a 
deeply dug and fairly moist border is far 
more to their taste, and at all events there 
are grand colonies of both R. podophylla and 
R. pinnata in excellent condition on the her¬ 
baceous borders here, which prove that, bog 
plants or not, they are admirable subjects for 
herbaceous borders, and as such should be 
largely used by all whose endeavour it is 
to specialise in this phase of gardening. 
Heather Bell. 
ON THE EDITOR'S TABLE. 
CARNATIONS from Bloxham. 
We are in receipt of a box of blooms of 
hardy border Carnations raised by Mr. Ernest 
Townsend, the Hollies Nurseries, Bloxham, 
Oxon. Owing to the diy weather the flowers 
are smaller than they would have been about 
the middle of July, but being no advocate 
of monstrous blooms we quite appreciated the 
neat forms of several of those sent. They 
have been cut from the original seedlings now 
four years old, but some of the plants carry 
upwards of 300 blossoms. We were very 
much pleased with a pale flesh variety named 
Pioneer, which might be taken for pure white 
at a short distance aw r ay. The blooms were 
very compact, and did not seem to split the 
calyx. A pure white one named Magnifica 
had larger blooms with a greater number of 
petals, and if properly displayed by the ex¬ 
hibitor would cover a good breadth of board. 
The darkest variety sent was Townsend’s 
Britannia, which was dark maroon-crimson 
and clove-scented. Equally, or more 
strongly, scented was that named Lydia, a 
fancy white ground Carnation with a heavy 
crimson edge. Standard Bearer had rela¬ 
tively few jietals, but of a brilliant scarlet 
colour. Meteor was the name given to a 
variety with rich rose flowers. 
All of the above have been selected accord¬ 
ing to the florist’s standard, with smooth, or 
nearly smooth, petals. A very charming 
yellow ground Picotee was that named 
Elegant. The petals are moderately nume¬ 
rous, the outer ones being rounded and well 
formed, with a delicate scarlet wire edge. In 
the way of a Picotee this is certainly a very 
refined flower, and could doubtless be grown 
to larger size if required for exhibition pur¬ 
poses by being disbudded. All of the above 
have been grown in the open border for four 
years, and are therefore perfectly hardy, the 
flowers having been cut from the original 
seedlings. 
Accompanying the above was a sweetly- 
scented American tree Carnation named Fair 
Maid. This had also been grown out of 
doors, but we presume only during the 
season. The colour is of the jialest flesh- 
pink, and reminds us somewhat of En¬ 
chantress. Some admirers selected this 
flower in preference to the others, probably 
not being florbts. 
