2l6 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
cone* After it advances well into the heart of the cone the tunnel becomes the 
egg-gallery, and single eggs are deposited at intervals in notches excavated along 
the sides of the burrow. The entire length of the egg-gallery is packed with saw- 
dust. Sawdust is also packed around the eggs in the egg notches, — A. D, W, 
Corsican Pine at Lochnaw. By Sir Andrew N. Agnew (Trans. Roy. Scot, 
Arb, Soc, vol. xxx. pp. 83-84; July 1916). — There is no tree which has come into 
general use in Wigtownshire during the last half-century which has proved 
so serviceable as the Corsican pine. At least that has been the experience on 
the Lochnaw estate, where it has been planted regularly for forty years. It 
is an extremely hardy tree, growing and thriving in the poorest soils and in the 
most exposed situations. The Corsican pine has the reputation of being difficult 
to establish, but it has given no trouble there. It is rather slow in taking hold of 
the ground, and is consequently apt to get a shake in stormy weather during its 
first year or two. But once this stage has been got over, it is the most reliable 
tree we have, making the best of any circumstances, and standing erect and 
unshaken in the teeth of the fiercest gales, 
The first Corsican pine planted at Lochnaw was in the year 1853, It is now 
a well-grown tree, 62 feet in height, with a gently tapering stem measuring 
5 feet 3 inches at 5 feet above the ground. 
The two things that catch the eye at once in a grove of the P, Laricio are the 
upright figure of the trees and the cylindrical shape of the stems. These two 
characteristics seem to mark out the tree as being specially adapted for pit-wood, 
There has been a great demand for home-grown timber for pit purposes since 
the war began, and to a lesser degree the demand is likely to be a permanent 
one,— A. D, W t 
Corylopsis Willmottiae. By A. O. (Irish Gard, xii. p. 37). — A fairly common 
plant in Western Szechwan, introduced from China by E. H. Wilson, A bushy 
deciduous shrub which should be planted on a warm south-west or west border. 
The soil should be light loam, leaf-mould, and peat, Propagate by layering in 
the summer, — E, T, E. 
Creosoting, The Riiping System of. By W, P, Greenfield (Quart, Jour, of 
Forestry, x. pp. 29-36 ; January 191 6). — On most well-managed estates of any 
size there is some method in vogue for preserving and extending the life of the 
timber used in estate buildings and for fencing and other purposes. Several 
methods have been tried for this end, such as impregnating A with naphthalene, 
or painting withsolignum &c, but the most common process is that of creosoting 
with heavy creosote oil. There are three different processes of creosoting — 
(1) by pressure — the most effective; (2) by immersing the timber in creosote 
and boiling for some hours ; (3) by simple cold immersion. 
The second method is most commonly in use on estates, because the initial 
expense of the boiler and tank is much less than that of the apparatus required 
to creosote by pressure. It affords very good results with certain species of 
timber, but in others there is not the same thorough saturation of the outer 
tissues as with creosoting under pressure. 
Formerly ordinary oak and larch fence posts would be rotten in about seven 
to eight years, but, by creosoting under pressure, inferior timber such as spruce 
can be used instead of good oak, which can be sold. The author has seen spruce 
fence posts thus creosoted that have stood in the soil for fifteen years, and when 
dug up the edges of the part that had been in the ground were still sharp, and 
even the saw kerfs could be seen. Plain spruce would have been rotten in a 
very few years, — A, D._ W t 
Crown-gall, Mechanism of Tumour Growth in. By Erwin F. Smith (Jour. 
Agr, Res. viii. Jan. 1917, pp. 165-186; 61 plates). — The ultimate cause of all 
proliferation in crown-gall is the micro-organism, Bacterium tumefaciens Sm. 
and T., but the mere mechanical irritation due to the introduction of a few 
rod-shaped bacteria in the tissues cannot be the direct cause of the proliferation, 
since other species of bacteria either have no specific action when inoculated 
into plants, or some quite different action, such as the wilting of the foliage due 
to the multiplication of bacteria into the vascular bundles (e.g. B. tracheiphilus), 
or a soft rot of the shoots and tubers (e.g. B. phytophthorus) . In each of these 
types of plant disease (tumour, wilt, or soft rot) the ultimate cause is a bacterial 
infection, but the immediate or proximate cause must be the chemical or physical 
actions of enzymes produced by the bacteria with a corresponding reaction on 
the part of the plant. 
The author now thinks that growth is not the result of external stimuli, 
but rather it is due to the removal of various inhibitions ; for, as he states, under 
