216 
NATURE 
[¥uly 8, 1886 
confined to the notes on animals, birds, reptiles, insects, 
and the parasitic torments of Brazil, notes on botany and 
on geology, together with a discussion of the theory of 
evolution and observations made on protective colouring 
and mimicry. 
With reference to the theory of evolution the author 
states that he has constantly endeavoured to oppose it, 
on the ground apparently put forward by theologians 
many years ago before they knew what the theory really 
was ; and we think that if our author will continue his 
scientific studies a little longer he will probably find that 
the arguments he uses against it are really not in point. 
By Walter 
(London : 
The Colloguial Faculty for Languages. 
Hayle Walshe, M.D. Second Edition. 
Churchill, 1886.) 
THIs is a book full of pleasant gossip round the central 
idea embodied in its title ; hence we have essays on the 
nature of genius, the conditions regulating colloquial 
faculty, and the causes of variety of colloquial faculty and 
faculty for translation. 
In the chapter on composition in foreign tongues it is 
pointed out that the man of science proves now and then 
well capable of wrestling effectively with the humorist on 
his own ground of the “tere humaniores, and gives as 
an example Herbert Spencer’s exfosé of abounding errors 
in a passage from Addison quoted by Matthew Arnold, as 
an example of classical English. 
We gather from our author that the English race is not 
the most gifted with the colloquial faculty, and a remark 
of Prince Bismarck’s is quoted that he had always found 
that an Englishman who could speak good French was a 
doubtful character. 
LETTERS TO LHE EDITOR 
{The Editor does not hold himself responsible for. opinions ex- 
pressed by his correspondents. Neither can he undertake to 
return, or to correspond with the writers of, rejected manu- 
scripts, No notice is taken of anonymous communications. 
[The Editor urgently requests correspondents to keep their letters 
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that it is impossible otherwise to insure the appearance even 
of communications containing interesting and novel facts.] 
Periodicity of Glacial Epochs 
PERMIT me to ask, as a matter of international comity in 
science, the help of my learned British colleagues in the follow- 
ing matter. 
I am just now occupied upon a work treating upon the 
periodicity of glacial epochs, a question which has already been 
broached by me in previous writings several years ago. The 
cause of this phenomenon being attributed by the astronomers, as 
well as by the majority of geologists, to the displacement of 
the perihelion, whose cycle is 21,000 years, it follows that, ac- 
cording to the actual position of this point, the ice now covering 
the Antarctic regions had its maximum of intensity at about the 
year £250 of our era. For the same reason, the ice of the 
boreal hemisphere must have offered at this same epoch its 
minimum of intensity. Consequently the latter must have been 
increasing since the close of the thirteenth century, while the 
former must have been receding. The researches of European 
geologists must have shown a marked extension of the glaciers 
of Spitzbergen, Greenland, &c., since the beginning of the 
fourteenth century, and a recession of vegetation from the lati- 
tude of Sicily to the Polar Circle. But we in France are not 
informed of what has happened in the southern hemisphere since 
the arrival of the first navigators. I would therefore, in the 
name of science, beg of any British officers, consuls, or scientific 
observers who are, or may have been, collecting facts at stations 
near the South Pole, in Patagonia, New Zealand, Tasmania, 
and elsewhere, to communicate to me directly, or through your 
colamns, any information they may have upon this subject. I 
wish to know whether, since the first arrival of Europeans in 
those regions, the ice field has shown a recessive movement, 
accompanied by an inverse tendency of vegetation. 
Tarascon, Ariége, June 27 ADOLPHE D’ASSIER 
Evidence of Man and Pleistocene Animals in North 
Wales prior to Glacial Deposits 
SOME of the results recently obtained during the researches 
carried on at the Tremeirchion caves under the superintendence 
of Mr. E. Bouverie Luxmoore and myself, seem to me of so 
much importance that I have thought it advisable to communi- 
cate them, in anticipation of the full report which will be pre- { 
sented to the British Association, especially as an important 
section is now exposed, and may be examined by any one de- d 
siring to do so, which will probably have to be covered before 
the end of the summer.? 
In continuing our explorations this year, by means of a grant 
from the British Association, we found that the Cae Gwyn 
Cave (described in my paper in the Quart. Fourn. Geolog. Soc. 
for February last) had come to an abrupt termination in a 
plateau of Glacial deposits. On further examination it was 
found that this must have been the main entrance into the — 
cavern when it was occupied by the Pleistocene animals, and 
that the Glacial beds in and upon it must have been deposited 
subsequent to the occupation by the animals. As in the other 
parts of the cavern, the cave-earth at the entrance—a brown 
sandy clay, contained fragments of a stalagmite floor and of . 
stalactites along with angular fragments of limestone. The 
bones also occurred at all angles, showing that the contents had : 
been greatly disturbed by water action. The bone earth was 
covered over at the entrance and for some distance inwards by 
a few feet of stratified sand, containing well-scratched boulders, 
and it, as well as the sand, was traced for a distance of fully 
6 feet beyond the entrance under the series of Glacial deposits, 
shown in the section. 
In digging outside the entrance, the floor of which is 20 feet 
below the surface of the field, it was soon found that we could 
not extend our researches outwards, owing to the nature of the 
lower deposits, chiefly sands and gravels, without making an 
opening into the field. By the kindness of the owner, Mr, 
Edwin Morgan, a shaft was allowed to be dug in front of the 
opening, about 9 feet across at the surface and over 5 feet at the 
bottom. This shaft was subsequently widened at the bottom, 
in consequence of some falls, and the lower part, except atone 
point, had to be carefully faced with timber. The upper part of 
the shaft is now much widened and sloped. To make it certain 
that the Glacial deposits are continuous from the shaft in a west- 
erly direction, I had the beds probed at different points for a | 
distance of about 70 feet ; and subsequent examination showed 
clearly that there is here an extensive terrace of drift reaching to 
heights of between 400 and 500 feet above Ordnance datum. 
The section was carefully taken at two different points in the 
shaft by Mr. C. E. de Rance, F.G.S., of the Geological Survey, 
and myself, and in doing so we found well-scratched boulders 
in each of the deposits. Aniong the boulders found are granites, 
quartzites, flint, felstones, diorites, volcanic ash, Silurian rocks, 
and limestone. Silurian rocks are mo-t abundant. It is clear 
that we have here some rocks from northern sources along with 
those from the Welsh hills, and the manner in which the lime- 
stone at the entrance to the cavern is smoothed from the north — 
would indicate that to be the main direction of the flow. A 
small but well-worked flint flake was dug up from the bone earth — 
on the south side of the entrance on June 28, in the presence of 
Mr. G. H. Morton, F.G.S., of Liverpool, and myself. Its posi- 
tion was about 18 inches below the lowest bed of sand. Several 
teeth of hyzena and reindeer, as well as fragments of bone, were 
found at the same place, and at other points in the shaft teeth of 
rhinoceros and a fragment of a mammoth’s tooth. One rhino- 
ceros tooth was found at the extreme point examined, about 
6 feet beyond and directly in front of the entrance. It seems 
clear that the contents of the cavern must have been washed out 
by marine action during the great submergence in mid-Glacial 
time, and that they were afterwards coyered by marine sands and 
by an upper boulder-clay, identical in character with that found 
at many points in the Vale of Clwyd, and in other places on the 
North Wales coast. ] 
The facts obtained seem to me to prove conclusively that man. 
and the Pleistocene animals must have lived in parts of the 
North Wales area, and have occupied some of the caverns, before 
the period of the great submergence indicated by the Moel 
Tryfaen and other high-level sands; hence certainly before the 
Upper Boulder-Clay was deposited. Henry Hicks 
* Tremeirchion is about four miles from St. Asaph, and less than two 
miles from Bodfari Station on the Chester Mold, and Denbigh line. 
