244 HEIGHT OF SNOW-LINE. [chap. XI 



not at all. These fruits, in corresponding latitudes in Europe, 

 are well known to succeed to perfection ; and even in this con- 

 tinent, at the Rio Negro, under nearly the same parallel with 

 Valdivia, sweet potatoes (convolvulus) are cultivated ; and 

 grapes, figs, olives, oranges, water and musk melons, produce 

 abundant fruit. Although the humid and equable climate of 

 Chiloe, and of the coast northward and southward of it, is so un- 

 favourable to our fruits, yet the native forests, from lat. 45° to 

 38°, almost rival in luxuriance those of the glowing intertropical 

 regions. Stately trees of many kinds, with smooth and highly 

 coloured barks, are loaded by parasitical monocotyledonous 

 plants ; large and elegant ferns are numerous, and arborescent 

 grasses entwine the trees into one entangled mass to the height 

 of thirty or forty feet above the ground. Palm-trees grow in 

 lat. 37° ; an arborescent grass, very like a bamboo, in 40° ; and 

 another closely allied kind, of great length, but not erect, flou- 

 rishes even as far south as 45° S. 



An equable climate, evidently due to the large area of sea 

 compared with the land, seems to extend over the greater part of 

 the southern hemisphere ; and as a consequence, the vegetation 

 partakes of a semi-tropical character. Tree-ferns thrive luxuri- 

 antly in Van Diemen's Land (lat. 45°), and I measured one 

 trunk no less than six feet in circumference. An arborescent 

 fern was found by Forster in New Zealand in 46°, where orchi- 

 deous plants are parasitical on the trees. In the Auckland 

 Islands, ferns, according to Dr. Dieffenbach,* have trunks so 

 thick and high that they may be almost called tree-ferns ; and 

 in these islands, and even as far south as lat. 55° in the Mac- 

 quarrie Islands, parrots abound. 



On the Height of the Snow-line, and on the Descent of the 

 Glaciers, in South America. — For the detailed authorities for 

 the following table, I must refer to the former edition : — 



Latitude. SflSSS? Observer, 



of Snow-line. 



Equatorial region; mean result 15,748 Humboldt. 



Bolivia, lat. 16° to 18° S. . . 17,000 Pentland. 



Central Chile, lat. 33° S. . . 14,500 to 15,000 Gillies, and the Author. 



Chiloe, lat. 41° to 43° S. . . 6,300 Officers of the Beagle, and the Author 



Tierra del Fuego, 54° S. . . 3,500 to 4,000 King. 



As the height of the plane of perpetual snow seems chiefly to 



* See the German Translation of this Journal : and for the other fact* 

 Mr. Brown's Appendix to Fllnders's Voyage. 



