258 TIERRA DEL FUEGO AND WEST COAST 



(such as the Patellae, Fissurellse, Chitons, and Barnacles), 

 according to Mr. G. B. Sowerby, are of a much larger size, and 

 of a more vigorous growth, than the analogous species in the 

 northern hemisphere. A large Voluta is abundant in southern 

 Tierra del Fuego and the Falkland Islands. At Bahia Blanca, 

 in lat. 39° S., the most abundant shells were three species of 

 Oliva (one of large size), one or two Volutas, and. a Terebra. 

 Now these are amongst the best characterised tropical forms. 

 It is doubtful whether even one small species of Oliva exists 

 on the southern shores of Europe, and there are no species of 

 the two other genera. If a geologist were to find in lat. 39° 

 on the coast of Portugal a bed containing numerous shells 

 belonging to three species of Oliva, to a Voluta, and Terebra, 

 he would probably assert that the climate at the period of their 

 existence must have been tropical ; but, judging from South 

 America, such an inference might be erroneous. 



The equable, humid, and windy climate of Tierra del P^uego 

 extends, with only a small increase of heat, for many degrees 

 along the west coast of the continent. The forests, for 600 

 miles northward of Cape Horn, have a very similar aspect. As 

 a proof of the equable climate, even for 300 or 400 miles still 

 farther northward, I may mention that in Chiloe (corresponding 

 in latitude with the northern parts of Spain) the peach seldom 

 produces fruit, whilst strawberries and apples thrive to perfec- 

 tion. Even the crops of barley and wheat ^ are often brought 

 into the houses to be dried and ripened. At Valdivia (in the 

 same latitude of 40° \\\\\\ Madrid) grapes and figs ripen, but 

 are not common ; olives seldom ripen even partially, and 

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

 Europe, are well known to succeed to perfection ; and even in 

 this continent, 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 

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

 to 38°, almost rival in luxuriance those of the .glowing inter- 

 tropical regions. Stately trees of many kinds, with smooth 

 and highly coloured barks, arc loaded by parasitical monocoty- 



^ Agiier6s, Descnp. Hist, dc la Prov. de Chiloe, 1791, ]"). 94. 



