Sir H. H. Howorth—The True Horizon of the Mammoth. 28 
M. Mortillet discusses another instance of which much has been 
made, and which is a good example of the slight basis upon which 
interglacial theories have been built. This is an alleged intercalation 
of stratified ““ancienne alluvion”’ between two glacial beds, in the 
gorge of the Drance, near Thonon (Haute Savoie). M. Mortillet says 
the Drance there cuts through some almost vertical calcareous beds; on 
the upturned edges of these beds there rest layers of alluvion, over 
which lie glacial beds. In some places in the gorge the calcareous 
beds have been denuded of their covering, and form a cornice; on 
to this cornice some of the glacial débris has slid down and made a 
kind of talus, looking at first sight as if it were overlain by the 
alluvion. The fallacy of this reading was tested by M. Mortillet, by 
making excavations on the spot,’ when it turned out that there was 
no intercalation whatever, but that the alluvion lay always under- 
neath the glacial beds. 
If we turn from the northern to the southern flanks of the Alps 
we shall find precisely the same evidence. At Careguano, at Lanzo, 
near Stura, at Giffenga in the Valley of the Cervo, at Boca, at Mag- 
giora and at Leffe (Gandino), there are certain lignites which are 
distinctly correlated by their Mammalian remains and other contents 
with the lignites of Utznach, Wetzikon, etc. Now it is a remark- 
able fact, as Gastaldi has shown, that these Italian beds rest directly 
upon Pliocene deposits and in no case, so far as it is known, do they 
have any glacial beds below them. The facts here quoted about 
North Italy have proved a stumbling block to Prof. James Geikie, 
who admits them, and admits that there are no traces in North 
Italy of former oscillations of climate (Gron Mae. 1872, Vol. IX. 
p. 256). He calls in that modern deus ex machina denudation to 
explain it. It seems to me very plain, therefore, that in the Alpine 
regions of Switzerland and its neighbourhood, the evidence shows 
that the Mammalian beds do not overlie the Drift, but when they 
occur together they are always covered by them. 
Let us now turn elsewhere. In the valley of the Inn, above 
Innsbruck at a place called Hotting, there is a breccia composed of 
stones from the Upper Triassic dolomite, of pieces of red sandstone, 
and of crystallized rock. This breccia contains remains of plant. 
Penck and others have declared this breccia to be underlaid as well 
as overlaid by moraine matter of glacial age, and the particular in- 
stance has been made much of by the advocates of interglacial mild _ 
periods. Unger and Stur, who have examined the plant remains, - 
have found among them leaves of fan palins and other evidences of a 
tropical climate, proving the beds to be of Tertiary age, and therefore 
outside the possibilities of being interglacial. I feel convinced that 
in other cases where the drift has been supposed to underlie the 
Pleistocene land-surface that Tertiary conglomerates more or less 
disintegrated have been mistaken for it. The conclusion for which 
Iam arguing is also supported by the evidence from the valley of 
the Rhone. Falsan, a most competent authority, writes as follows: 
“ Durant nos études avec M. E. Chantre sur le terrain erratique du 
1 Le Préhistorique, p. 312. 
