178 WHAT MR. DARWIN SAW. 



PATAGONIA. 



though not known to be active, must be in their origin vol- 

 canic. The line of the Andes is not, in this neighborhood, 

 nearly so elevated as in Chile; neither does it appear to 

 form so perfect a barrier between the regions of the earth. 

 This great range, although running in a straight north and 

 south line, always appeared more or less curved. 



FOSSIL TREES. 



IN the central part of the Uspallata range, at an eleva- 

 tion of about seven thousand feet, I observed on a bare 

 slope some snow-white projecting columns. These were pet- 

 rified fir-trees, abruptly broken off, the upright stumps pro- 

 jecting a few feet above the ground. The trunks, some fifty 

 in number, measured from three to five feet each in circum- 

 ference. They stood a little way apart from each other, but 

 the whole formed one group. I confess I was at first so 

 much astonished that I could scarcely believe the marvellous 

 story which this scene at once unfolded. I saw the spot 

 where a cluster of fine trees once waved their branches on 

 the shores of the Atlantic, when that ocean (now driven back 

 seven hundred miles) came to the foot of the Andes. I saw 

 that they had sprung from a volcanic soil, which had been 

 raised above the level of the sea, and that afterward this 

 dry land, with its upright trees, had been let down into the 

 depths of the ocean. In these depths the formerly dry land 

 was covered by beds of sediment, and these again by enor- 

 mous streams of submarine lava one such mass attaining 

 the thickness of a thousand feet ; and these deluges of molten 



