356 
THE GARDENING WORLD 
April 29, 1905. 
others, and some other types may appear most happy in either 
grit or limestone. 
In all these cases the soil must bei of some considerable depth, 
so that the roots may penetrate and be beyond the reach of 
drought and the fluctuations of temperature in summer. It 
may be remembered that many mountain plants possess roots 
of a length out of proportion to the size of the plant. Even 
when growing in rocky places, these long roots are of immense 
advantage by penetrating the seams and crevices between the 
rocks. He considers that an ideal situation for a rock garden 
is an open slope built so as to receive the roots of plants in 
places, and have bold rocks projecting here and there. 
Several excellent views of the alpine plants at Kaimes Lodge 
have been illustrated by photographic reproductions. Amongst 
them are views of the Edelweiss, the Himalayan Cowslip 
(Primula si'kkimensis), the Alpine Windflower, some Bock 
Roses, Saxifraga. Dr. Ramsay, and a full-page illustration gives 
an excellent view of Mr. Lindsay’s rock garden, or,, rather, one 
steep portion of it, showing several plants flowering profusely. 
The Saxifraga above mentioned is described as a, hybrid be¬ 
tween S. macnabiana and S. lantoscana superba, and shows a 
plant with a longer panicle of flowers than occurs in the first- 
named plant, which is also a hybrid. 
Referring to the loss of alpine plants, which is of frequent 
occurrence under cultivation, he says that for one lost by un¬ 
suitable soil and exposure, ten are overrun by some rampant 
grower such as a Crucifer or a. Composite. For this reason, 
the rock builder and planter should take care to have the 
pockets intended for alpine® separated by means of stones, and 
the rampant growers severely held in check or kept to their 
own quarters. The writer questions; the good taste in plant¬ 
ing subjects that are really tender in a rock garden, and men¬ 
tions Primula verticillata as an example. Seeing that there is 
an all-sufficiency of alpines from which to choose, there is no 
necessity for attempting the impossible by trying to grow 
things that are unfitted for the climate, besides being in bad 
taste. He finishes up this article by giving a long list of plants 
suitable for the rockery, and it will be seen that really good 
things are relatively plentiful. 
An interesting chapter is that on hybridisation by Dr. 
Wilson, of St. Andrews University. The paper covers a good 
deal of ground, making many allusion's to work done by people 
in foreign countries. Under the name of unassisted crosses he 
discusses a number of natural hybrids. A fairly frequent one 
is that of the Primrose and Cowslip, the resulting progeny of 
which he says is indistinguishable from the Oxlip. This may 
refer to the so-called English Oxlip, which is in reality a Poly¬ 
anthus rather than the wild Oxlip (Primula, elatior), which 
grows only in isolated localities in four English counties. Ihe 
true Oxlip is usually regarded as a distinct species, and is 
easily recognisable by its" smooth throat, whereas the cross 
between the Primula and the Cowslip retains the five little 
swellings of both its parents in the throat. 
Under the name of “ popular delusions ” he once more warns 
the public of the mistakes concerning hybrids which usually 
pass muster in the 1 lay Press. One of these is the peloria. of the 
upper flower of the Foxglove, which some have described as a 
cross between the Foxglove and the Canterbury Bell. Another 
one of a similar character is the Strawberry-Raspberry, which 
he admits is a true species, though most- people disagree as to 
its proper name. It is here named Rubus rosaefolius, and R. 
sorbifolius is said to be a synonym. It is certainly allied to 
the first-named, but has very little resemblance to its supposed 
svnonym. While we suppose the professor accepts the names 
which pass muster in gardens, we may state once more that all 
the accepted names for this Bramble in British gardens are 
mistakes, as the species has been described by the ardent 
German authority on Rubi, Hen’ Focke. This botanist admits 
that it is closely allied to R. rosaefolius, but that it bears its 
flowers in a terminal cluster, whereas the last-named may boat- 
many clusters on lateral shoots like the ordinary Raspberry. 
The name of the Strawberry-Raspberry is therefore Rubus file- 
cebrosus Focke. 
Very interesting also are the _crosses between the Black 
Currant and the Gooseberry. The Doctor has also produced 
a hybrid between the Gooseberry and the Flowering Cun-ant. 
Illustrations of both of them are here given. The first-named 
of these hybrids has several times been raised, and flowers 
freely, but fruits very sparingly. The hybrid between the 
Gooseberry and Flowering Cun-ant is a strong bush, but has 
never yet flowered. Another hybrid between the Sweet Brier 
and the Scotch Rose grew for ten years before it flowered. 
The paragraph on graft hybridisation refers to Laburnum 
Adami, and shows the two parents, together with the hybrid 
which frequently reverts to one or other of the parents. 
A few interesting remarks are made concerning Potatos 
while discussing Mendel’s theory. In crossing a red and white 
variety the seedlings proved a very mixed lot, with purple, red, 
pink-eyed and white tubers. This might have been the result 
of crossing the red and white, but. some of the varieties which 
turned up may have had reference to some previous ancestor. 
A mixed lot was also produced by the crossing of two white 
varieties giving tubers resembling some of the early varieties 
known in cultivation, so that here we should certainly have 
evidence of reversion. 
While discussing the subject of “ experiences,” he describes 
the errors and pitfalls into which many workers in this line are 
likely to fall. They make crosses with all due deliberation or 
care, but do not take the trouble to prevent access of insects, 
consequently the seedlings prove a very mixed lot when they 
come into bloom, and the parentages, if recorded, are liable to 
be altogether wrong or misleading. He had been told of a 
galaxy of crosses of certain plants amongst which he had been 
working, but when he examined the samples he failed to find 
a single cross amongst them. Another result of crossing 
amongst certain plants is seedless fruits, and this, he says, 
is veiy frequent amongst the Passion Flowers, even although 
the fruit looks plump and good. 
Another careless method of procedure on the part of some 
is to spend a. considerable time in pollinating a large number 
of flowers which they do not take the trouble to protect from 
insects, relying upon the number of crosses to secure something 
good. In practice this means the occupation of a considerable 
area of ground with seedlings that, may turn out worthless 
when they come into bloom. He advises the careful selection 
of parents furnishing the qualities or characters it is desired 
to impart to the seedlings. In conclusion, he quotes Luther 
Burbank as stating that “ plant, breeding is in its earliest in¬ 
fancy.” Another writer describes this method of improving 
plants as the “ greatest industry to which science has ever yet 
been applied.” 
Other useful, interesting and suggestive papers are “ Roses, 
Past and Present,” by the late Hugh Dickson; “Herbaceous 
Plants,” by R. P. Brotherston; “ Classification of Apples,” by 
P. Murray Thomson, who also discusses the Black Cun-ant Gall 
Mite; and the “ Cultivation of Carnations all the 1 ear 
Round,” by Daniel Kidd. 
The New Tree Heath. 
Erica Veitchi and its Parents. 
(i See Supplement.) 
On a former occasion we discussed the supposed natural 
hybrid Tree Heath (Erica Veitchi), and being now in a position 
to give illustrations of it, as well as of its parents, we may now 
describe their chief differences. 
E. arborea, to which the name Tree Heath is chiefly applied, 
has nearly globular white flowers, somewhat inflated or 
widened above the base and decidedly contracted at the mouth. 
It is, therefore, intermediate between urn-shaped and globular. 
These flowers are flesh coloured in the bud, gradually fading 
to white as they expand, and are usually produced in clusters 
of three at the ends of the short, side branches, or spur-like 
twigs. These clusters are very often crowded, owing to the 
short-jointed character of the Tree Heath. The stem is 
usually more hirsute than that of any of its relatives, unti 
the primary skin gets thrown off. - The leaves are of rich dar 
