THE VOYAGE OF THE BEAGLE 253 



the drier eastern parts of the country ; and the deer has never 

 been seen south of the Strait of Magellan. Observing the 

 general correspondence of the cliffs of soft sandstone, mud, 

 and shingle, on the opposite sides of the Strait, and on some 

 intervening islands, one is strongly tempted to believe that the 

 land was once joined, and thus allowed animals so delicate 

 and helpless as the tucutuco and Reithrodon to pass over. 

 The correspondence of the cliffs is far from proving any 

 junction; because such cliffs generally are formed by the 

 intersection of sloping deposits, which, before the elevation 

 of the land, had been accumulated near the then existing 

 shores. It is, however, a remarkable coincidence, that in the 

 two large islands cut off by the Beagle Channel from the 

 rest of Tierra del Fuego, one has cliffs composed of matter 

 that may be called stratified alluvium, which front similar 

 ones on the opposite side of the channel, while the other is 

 exclusively bordered by old crystalline rocks : in the former, 

 called Navarin Island, both foxes and guanacos occur ; but in 

 the latter, Hoste Island, although similar in every respect, 

 and only separated by a channel a little more than half a mile 

 wide, I have the word of Jemmy Button for saying that 

 neither of these animals are found. 



The gloomy woods are inhabited by few birds: occasion- 

 ally the plaintive note of a white-tufted tyrant-flycatcher 

 (Myiobius albiceps) may be heard, concealed near the sum- 

 mit of the most lofty trees ; and more rarely the loud strange 

 cry of a black wood-pecker, with a fine scarlet crest on its 

 head. A little, dusky-coloured wren (Scytalopus Magellani- 

 cus) hops in a skulking manner among the entangled mass 

 of the fallen and decaying trunks. But the creeper (Oxyurus 

 tupinieri) is the commonest bird in the country. Through- 

 out the beech forests, high up and low down, in the most 

 gloomy, wet, and impenetrable ravines, it may be met with. 

 This little bird no doubt appears more numerous than it 

 really is, from its habit of following with seeming curiosity 

 any person who enters these silent woods: continually utter- 

 ing a harsh twitter, it flutters from tree to tree, within a few 

 feet of the intruder's face. It is far from wishing for the 

 modest concealment of the true creeper (Certhia familiaris) ; 

 nor does it, like that bird, run up the trunks of trees, but 



