440 NATURE [MarcH I0, 1904 
whole. The overfolded mountain limestone of Fig. 1, | way of their necessary supplies of water. Similar 
covered by Boulder-clay, presents many points of | instances of autumn flowering are familiar to 
interest; the duplication of the fold, just behind the 
figure in the foreground, is particularly well shown, 
and the various behaviour of the beds in the anticlinal 
to the right is most instructive, as is the onion-shaped 
synclinal, which succeeds it. The second figure illus- 
trates part of an ancient Carboniferous forest which 
extends over a considerable area around Glasgow, and 
is not seldom exposed by quarrying operations. The 
trunks of the trees are rooted in dark coloured carbon- 
aceous shales, and covered with grey sandy shales 
and flaggy sandstones, in which their débris— 
branches and fragments of bark—lies scattered ; over- 
lying the whole is a sill of intrusive dolerite (un- 
fortunately quarried away, and so not shown in the 
figure), to which possibly they owe their preservation. 
It is very gratifying to know that steps have been 
taken to protect this interesting exposure from the 
weather by roofing it over, though the scene must 
thereby lose some of the picturesqueness suggested by 
the photograph, where the contrast of the graceful 
living trees with the stumps of the extinct and 
monstrous Cryptogams (one of these measures 3 feet 
in diameter) has a very pleasing effect. 
The committee is to be congratulated upon the 
great and general excellence of the work, and the 
editor of the series for the admirable judgment he has 
displayed in making a selection from the vast amount 
of material at his disposal. 
ACTION OF ANAESTHETICS ON PLANTS. 
ar 
I autumn is startled to find horse-chestnuts and other 
spring-flowering trees producing a second crop of 
flowers. A similar occurrence is not infrequent in pear 
or apple trees and in the common laburnum. This 
autumnal flowering is due to one of two causes. In 
some cases after the flowers have been produced on the 
‘fold wood”’ or on short “spurs,’’ the Kurztriebe of the 
Germans, formed in the previous autumn, other flowers 
are produced on the long shoots of the present year. The 
difference in the general appearance of a tree producing 
its flowers on the ‘‘ spurs ”’ and of one where the blos- 
soms are produced on the ‘‘ extension shoots ’’ is often 
greater than that observable between distinct species, 
and yet, of course, there is no specific difference be- 
tween them. The autumnal production of flowers on 
the yearling shoots is generally assigned, but in a 
vague, indeterminate fashion, to changes in external 
conditions. Be that as it may, there are some varieties 
such as the Napoleon pear which every year behave in 
this fashion. The operations of pruning are regulated 
by the way in which the buds:are produced on the old or 
on the new wood of the year, so that the gardener has 
to take cognisance of appearances which might be, and 
indeed are, generally ignored by the systematic 
botanist. ‘ 
Another cause of autumnal flowering is due to pre- 
cocity or anticipation. This is the matter which in 
particular has suggested this note. The flower buds 
are formed in their usual place, but, for some reason 
or other, growth and development are hastened, and 
the flowers which in ordinary circumstances should un- 
fold in the following spring are seen to expand in 
autumn. 
In one of the squares in Paris last autumn the whole 
or the greater part of the horse-chestnut trees were in 
bloom, young foliage being interspersed among the 
flowers. On closer examination it was seen that the 
older leaves had almost all fallen prematurely or were 
shrivelled up as if the roots.had been deprived in some 
NO. 1793, VOL. 69] 
not unfrequently happens that the passer-by in | 
observers, and they seem generally to be due to summer 
drought, to removal at an unpropitious period, or to 
any cause which interferes with the normal course of 
nutrition, Allusion is made to these phenomena 
because they throw light on the experiments of 
Johannsen, of Copenhagen, who was the first to 
show the effect of ether vapour in hastening the 
flowering period of various shrubs. The action of the 
vapour of chloroform and that of ether in arresting 
the movements of the leaflets of the sensitive plant 
(mimosa) have long been known, but the action has 
been considered to be purely local. 
Matters were in this state when Johannsen pushed 
his experiments further, and in a different direc- 
tion, and proved that the flowering of lilacs could 
be hastened by exposure to the vapour of ether. 
He thought that if he:shortened the resting stage of 
the shrubs during which their activity is dormant, he 
would be enabled to induce the earlier and more rapid 
production of flowers. Exposure to the vapour of ether 
he found arrested the growth of the plant and secured 
its earlier and more complete ‘‘ rest.’’ Johannsen’s ex- 
periments have been repeated on a large scale in Ger- 
many and in France, the general method of procedure 
being the following. Ina case. as nearly air-tight as 
possible, the lilac bushes are placed at a temperature of 
about 65° F. Light is excluded. From the top of the 
| case is suspended a small cup into which the ether is 
poured by means of a funnel through an aperture, made 
for the purpose, and immediately closed. Owing to the 
| explosive nature of the vapour the greatest care must 
be taken to avoid the presence of any flame. Thirty or 
forty grammes of ether are enough for a hundred cubic 
litres of air. The plants are subjected to the influence 
of the vapour for forty-eight hours. On their removal 
from the ether chamber the leaves fall, if they have not 
already done so. The plants are then removed to a cool 
house and gradually subjected to forcing in the ordinary 
| Manner. 
By these means the expansion of the blooms is - 
hastened, the etherised plants producing their blooms 
several days before those treated in the ordinary 
manner. The gain of a few days is a matter of great 
importance to the grower for market in the winter 
season, as he gets so much better a price for his goods. 
Moreover, the cost of fuel is reduced, for the same 
amount of heat is not required for forcing, as we 
have seen that the time required is diminished. Not 
only lilacs, but many other flowering shrubs have been 
experimented upon, and with such good results that 
the process has been adopted on a large scale, and in 
our own country Mr. Jannoch has, we learn, adopted 
the plan with most successful results. 
A writer in the Jardin of January 20 narrates how he 
exposed plants of lilacs to the vapour of ether in the 
manner above described on December 7, removed 
them to the greenhouse on December 9, andon January 
1 the flowers were sufficiently expanded for use in the 
decoration of his apartments. Other varieties followed 
at a few days’ interval. Spiraea Thunbergii etherised 
on December 7 was in full bloom on December 24. 
M. Minier, who made these experiments, placed his 
apparatus in a temperature of 139-16° C., and the 
plants were subjected to the ether vapour for forty 
hours. They were afterwards placed in a house where 
the temperature ranged from 13°-16° C. at night to 
15°-18° C. by day. 
The photographs showing the contrast between the 
etherised and the non-etherised plants are very remark- 
able and bear witness to the value of the process in 
securing bloom in the dull season when the chrysan- 
themums are beginning to go off. It is noteworthy 
