The Geographical Journal (Journal of the Royal Geographical Society): Volume XVI, No. 6 [‎377v] (107/232)

680
THE MONTHLY RECORD.
of Bala lake, into the valley of the Wnion, is indicated also by the apparent slope
of the lake-floor in that direction, and by the existence of an extensive alluvial
plain at the present foot of the lake, even larger than that now being formed at
its head Mr. Lake shows that in the direction of the Wnion valley there is no
evidence that the lake is rock-bound, but that the old channel was probably
blocked by drift, the reversal of the drainage being due, however, in part, to Larth-
movements. The lake and valley adjoining it to the south-west lie in a trough
between faults, which seem to have played an unusually important part m the
production of the present topography, the present low watershed The boundary between adjacent drainage basins. across the valley
corresponding in position with other, oblique, faults. Passing to the consideration
of the general drainage system of North Wales, the writer The lowest of the four classes into which East India Company civil servants were divided. A Writer’s duties originally consisted mostly of copying documents and book-keeping. draws attention to the
important series of deep valleys running for long distances from north-east to
south-west, although interrupted, in certain cases, by low watersheds. The most
marked of these lie on a straight line running from Ogwen lake to the head of the
Wnion valley, and their position is probably due to Earth-movements. The valleys
referred to cut up the whole country into parallel strips drained (generally south
wards) into those valleys by another system of streams, the units of which can
frequently be traced from one strip to the next, and which appear to represent
a former drainage system, radial in character, having its centre near the sources
of the Conway. This system—very similar to that now in existence in the Lake
District—seems to have been subsequently modified by the formation of the
present transverse valleys, in one of which Bala lake was formed.
Influence of Latitude on Plant-life in Germany.— Prof. Ihne, of Darm
stadt, who has paid much attention to the phenomena of plant-growth as influenced
by locality, and has superintended a careful series of observations in Germany for
the purpose of elucidating the question, sets forth, in the seventh number of the
Geographische Zeitschrift, the results obtained as regards the influence of latitude
on the dates at which spring is announced by the bursting into flower of various
typical trees and shrubs. By the method adopted, which is described at the outset
of the paper, the first appearance of the leaf (though recorded in the observations)
has not been taken into consideration, owing to the greater difficulty of obtaining a
trustworty record of this than of the dates of flowering, while, given careful observa
tion, the results arrived at may be taken to be the same. Mathematical accuracy is,
of course, not to be expected, and the results as a whole are not invalidated by the
impossibility of selecting stations at which observations for a sufficient number of
years have been carried out, and where other factors besides latitude—longitude,
altitude, exposure, soil, etc.—are the same. In his present investigation. Prof. Ihne
has chosen localities differing as little as possible in these respects. All lie more or
less in a line from north to south, the average difference of longitude being only 46
kilometres (28 J miles); and from his previous researches into the influence of longitude
on the phenomena in question, which showed that for stations of moderate elevation
in Central Europe, the advent of spring is retarded by 0-95 day for every 111 kilo
metres (60 geographical miles) in an easterly direction, Prof. Ihne shows that such
a difference may well be left out of consideration. From the differences observed
in the case of eight pairs of stations, which, when reduced to the unit of 1° of
latitude (111 kilometres), show intervals of time for that distance varying from
3-4 to 4'6 days, Prof. Ihne arrives at the conclusion that for every additional
degree of latitude the advent of spring is retarded by about four days.
ASIA.
Burma-Sechuan Railway Survey. —Among the many railway projects
set on foot within the past few years for the opening up of China, one of the most