﻿J. 8. Gardner — Development of Plants. 277 



crest surrounding the cirque, and sloping to it, is only some metres 

 broad, so that it cannot feed even a very small stream." But in all 

 the cirques that I have seen there are the streams. In Gavarnie, the 

 Fer a 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 

 sujDplied 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. 



V. — Qn Baron G. von Ettingskausen's Theory of the Develop- 

 ment OF Vegetation on the Earth. 



By J. Starkie Gardner, F.G.S. 



11. The Tertiary Elements of the European Flora. 



[Alls dem LXIX. Bande der Sitzb. der k. Akad. der Wissensch. I. Abtli. Marz- 

 Heft, Jahrg. 1874.] 



THE 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 imjDortant 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 

 ProteaceEB, belonging to the genera Banlcsia, Dryandra, Hahea, 

 Persoonia and Lomatia, and FetropMloides (of the latter the fruit 



