MESTIZO PLANTATION'S. 
205 
the two formations lying upon each other, the beds of the 
limestone of Cumanac-oa, which I consider as an Alpine 
limestone, are always largely mixed with clay and marl. 
Lying, like the mica-slate of Araya, north-east and south- 
west, they are inclined, near Punta Delgada, under an angle 
of 60 degrees to south-east. 
We traversed the forest by a narrow path, along a rivulet, 
which rolls foaming over a bed of rocks. We observed, that 
the vegetation was more brilliant, wherever the Alpine lime- 
stone was covered by a quartzose sandstone without petrifac- 
tions, and very different from the breccia of the sea-coast. 
The cause of this phenomenon depends probably not so much 
oti the nature of the ground, as on the greater humidity of 
the soil. The quartzose sandstone contains thin strata of a 
blackish clay-slate,* which might easily be confounded with 
the secondary thonschiefcr ; and these strata hinder the 
water from filtering into the crevices, of which the Alpine 
limestone is full. This last offers to view here, as in Saltz- 
burg, and on the chain of the Apennines, broken and steep 
beds. The sandstone, on the contrary, wherever it is seated 
on the calcareous rock, renders the aspect of the scene less 
wild. The hills which it forms appear more rounded, and 
the gentler slopes are covered with a thicker mould. 
In humid places, where the sandstone envelopes the Alpine 
limestone, some trace of cultivation is constantly found. 
We met with huts inhabited by mestizoes in the ravine of 
Los Trades, as well as between the Cuesta de Caneyes, and 
the Bio Guriental. Each of these huts stands in the centre 
of an enclosure, containing plantains, papaw-trecs, sugar- 
canes. and maize. We might be surprised at the small 
extent of these cultivated spots, if we did not recollect that 
an acre planted with plantainsf produces nearly twenty times 
as much food as the some space sown with com. In Europe, 
our wheat, barley, and rye cover vast spaces of ground ; and 
in general the arable lands touch each other, wherever the 
inhabitants live upon corn. It is different under the torrid 
zone, where man obtains food from plants which yield more 
abundant and earlier harvests. In those favoured climes, 
the fertility of the soil is proportioned to the heat and 
humidity of the atmosphere. An immense population finds 
* Schiefertlian. + Musa paradisiaca. 
