J. S. Gardner — Development of Plants. 
277 
cresfc surrounding the cirque, and sloping to it, is only some metres 
broad, so that it cannot feed even a very small stream.” ßut in all 
the cirques that I have seen tliere are the streams. In Gavarnie, the 
Fer ä Cheval — all that I have described, and many more besides, the 
streams are so marked a feature, that even the passing traveller 
cannot fail to notice them. Sometimes they are supplied by ledges, 
which, though almost invisible from below, are large enough to Sup- 
port permanent snow-beds ; for instance on such a precipice as that 
of the Creux de Champs, a bed as broad as Regent Street would from 
below seem a mere streak. Sometimes they may be fed by springs ; 
sometimes it may be that the work of erosion is coming to a stand- 
still for want of a sufficient feeding ground, and the streams are 
supplied only by the rain drainage of the clifF itself. More than once 
it has been rather a puzzle to me how those which I saw were 
supplied. But be this as it may, I have never yet seen a cirque 
without abundant streamlets ; evidenced by the gulleys and water 
stains in some places, by the actual runlets in others, and by the 
talus heaps below all. Hence I conclude that the theory of water 
excavation as applied to all cases, big and little, in hot countries as 
well as cold — so far as my experience goes — is better than that of ice 
excavation, which seems mechanically almost impossible, and leads 
us to conclusions about the formation of valleys which I think most 
physiographers will admit to be untenable. 
Y. — On Baron C. von Ettingshausen’s Theoky of the Develop- 
ment of Vegetation on the Earth. 
By J. Starkie Gardner, F.G.S. 
II. The Tertiary Elements of the European Flora. 
[Aus dem LXIX. Bande der Sitzb. der k. Akad. der Wissensch. I. Abth. März- 
Heft, Jahr». 1874.] 
T HE following is an abstract of another of the papers forwarded 
to me from Graz, to which I alluded in the April Number of the 
Geological Magazine. The author first States that the opinion he 
had formed, that all the Floras of the present time were represented 
in the Tertiary Flora of Europe, has been still more confirmed by 
later researches, and then enters upon his more immediate subject. 
Of all the groups of plants comprised in our Tertiary Floras, 
those which resemble the Australian forms are the most striking and 
deserve our first attention, as their peculiar and unmistakable charac- 
ters show more than those of any other group, how a Flora, now 
completely exotic and distinct, was once fully represented in all its 
more important elements, in Europe. The Tertiary strata of Europe 
contain all the characteristic families of the present Australian Flora, 
represented by many distinctive genera ; thirteen families only, 
and these of small extent, not being hitherto found. The leaves 
of Australian plants are very characteristic and easily recognized; 
and there exist, as well as leaves, either fossil fruits, or seeds of the 
Proteaceae, belonging to the genera Banlcsia, Dnyandra, Halcea, 
Persoonia and Lomatia, and Petrophiloides (of the latter the fruit 
