398 AMAZONIA AND LA PLATA. 



Not a single indigenous tree is met in the true pampa, and those now growing, 

 even far from human habitations — eucalyptus, poplar, peach, and others — have 

 all been introduced by man. Conspicuous amongst them is the ombu {phjtolacca 

 ovpircunia dioica), with a huge spongy stem, dull bail-shaped foliage, and gnarly 

 roots trailing over the surface. 



Southwards the pampas flora scarcely extends beyond Bahia Blanca ; but far- 

 ther inland it still reaches the Colorado valley, which may be taken as the northern 

 limit of the scrubby vegetation of Patagonia. In this zone there is a total absence 

 of pasturage properly so-called, although a few tufts of grass and other herbs grow 

 about the stems of the thorny and gnarly shrubs. In the whole of the vast Pata- 

 o-onian region Lorentz and Niederlein had enumerated not more than 300 distinct 

 species in 1884. Here the prickly cactus presents in many places an impassable 

 barrier to men and horses. In the Hio Negro valley the only large tree is a species 

 of willow (sali,r huDiholdficaia), which may, perhaps, be of European origin. But 

 even this is rapidly disappearing under the axe of the woodman. On the terraces 

 dominating the river banks the most common " tree," a mere shrub in appearance, 

 is the chnnar {gourUœa decorficam), which in October decks itself with yellow flowers 

 resembling the broom. 



Amongst the few Patagonian plants possessing some economic value are the 

 " incense " tree (ditraua magcUanica), which yields an excellent resin, and the Santa 

 Cruz "tea" [micromeria DarwinU), a very small plant, with the leaves and large 

 roots of which is made a highl}^ aromatic infusion tasting like mint. The bcrberis 

 hiuifolia grows in such abundance on certain inland dunes that its bluish colour 

 is visible miles away, and when the supply of guanaco meat fails, the Indians live 

 exclusively on the berry of this plant. From a sj)ecies of juniper they obtain the 

 so-called maken, a gum which all Patagonians chew, and which acts both as an 

 excellent dentifrice and as a substitute for tobacco. 



About the sources of the Santa Cruz the slopes of the Cordilleras are clothed 

 with continuous forests of the " antarctic beech," which intertwines its branches 

 above the gorges, where the wild horse has taken refuge. Farther north the 

 hillsides are covered with " oaks " and " cypresses," while the apple, introduced 

 by the Jesuits, flourishes vigorously in the upland valleys, where the head- 

 streams of the Rio Negro take their rise. 



Fauna of Argentina. 



During tertiary and even quaternary times, the southern regions of the Con- 

 tinent had a far richer fauna of large animals than at present. The deposits of 

 fossil mammals discovered by Darwin near Bahia Blanca were embedded in a layer 

 of stratified gravels and of reddish mud, such as might at present be formed by 

 the sea on a shoaling beach. The associated shells belonged in fact to recent or 

 even contemporary species. Most of the glyptodons or gigantic armadillos brought 

 to light in the pampean formation just below the vegetable humus are as perfect 

 as the skeletons of horses or oxen Iving on the surface. Hence the conditions of 



