THE VOYAGE OF THE BEAGLE 



213 



on which this monument of a great convulsion of nature now 

 lies. As the fragments in the valleys are neither rounded 

 nor the crevices filled up with sand, we must infer that the 

 period of violence was subsequent to the land having been 

 raised above the waters of the sea. In a transverse section 

 within these valleys, the bottom is nearly level, or rises but 

 very little towards either side. Hence the fragments appear 

 to have travelled from the head of the valley; but in reality 

 it seems more probable that they have been hurled down from 

 the nearest slopes; and that since, by a vibratory movement 

 of overwhelming force, 9 the fragments have been levelled 

 into one continuous sheet. If during the earthquake 10 which 

 in 1835 overthrew Concepcion, in Chile, it was thought won- 

 derful that small bodies should have been pitched a few 

 inches from the ground, what must we say to a movement 

 which has caused fragments many tons in weight, to move 

 onwards like so much sand on a vibrating board, and find 

 their level ? I have seen, in the Cordillera of the Andes, the 

 evident marks where stupendous mountains have been broken 

 into pieces like so much thin crust, and the strata thrown on 

 their vertical edges; but never did any scene, like these 

 " streams of stones," so forcibly convey to my mind the idea 

 of a convulsion, of which in historical records we might in 

 vain seek for any counterpart: yet the progress of knowledge 

 will probably some day give a simple explanation of this 

 phenomenon, as it already has of the so long-thought inexpli- 

 cable transportal of the erratic boulders, which are strewed 

 over the plains of Europe. 



I have little to remark on the zoology of these islands. I 

 have before described the carrion-vulture of Polyborus. 

 There are some other hawks, owls, and a few small land- 

 birds. The water-fowl are particularly numerous, and they 

 must formerly, from the accounts of the old navigators, 

 have been much more so. One day I observed a cormorant 

 playing with a fish which it had caught. Eight times suc- 



9 " Nous n'avons pas ete moins saisis d'etonnement a la vue de l'innom- 

 brable quantite de pierres de jtoutes grandeurs, bouleversees les unes sur 

 les autres, et cependant rangees, comme si elles avoient ete amoncelees 

 negligemment pour remplir des ravins. On ne se lassoit pas d'admirer les 

 effets prodigieux de ia nature." — Pernety, p. 526. 



10 An inhabitant of Mendoza, and hence well capable of judging, assured 

 me that, during the several years he had resided on these islands, he had 

 never felt the slightest shock of an earthquake. 



