Chapter VI

Darwin hires a Gaucho guide and departs Bahia Blanca, noting the difficult four-hundred-mile journey through uninhabited country on a desolate plain of crumbling calcareous rock.

Darwin evaluates the Rio Sauce, correcting the Jesuit Falconer's claim that it is a considerable river by arguing it must originate from Andes snowmelt based on periodical floods, yet noting current conditions suggest smaller seasonal sources.

Darwin travels to Sierra Ventana, noting rumors of coal and mineral deposits that prove unfounded, and observing the mountain's distinctive isolated appearance and geological composition.

Darwin describes his challenging climb up Sierra Ventana, experiencing leg cramps that prevent him from reaching the highest peaks but allowing him to accomplish his geological purposes.

Darwin analyzes the white quartz rock and conglomerate formations on Sierra Ventana, inferring these pebbles were aggregated when calcareous formations deposited beneath the sea.

Darwin reflects that while the view was insignificant, the novelty and minor danger made the experience valuable, and notes comfortable sleep despite harsh conditions.

Darwin returns to Sauce posta, hearing accounts of previous Indian attacks at Sierra Ventana and observing wildlife including deer and guanaco.

Darwin travels to the third posta, hearing about animal losses to predators and storms, and encounters a friendly Indian tribe led by Bernantio traveling to a salt mine.

Darwin observes soldiers practicing with bolas, describes their effectiveness at various distances, and recounts an anecdote from the Falkland Islands demonstrating their striking force.

Darwin describes the diverse ethnic makeup of the soldiers and their harsh living conditions, noting their vigilance against Indian attacks and limited food and fuel.

Darwin describes coordinated hunting strategies used to drive wild animals together, observations of partridges and foxes, and the discovery of a puma kill and ostrich nest.

Darwin departs the third posta with soldiers, declining to offer monetary remuneration to his host based on local hospitality customs that refuse payment.

Darwin travels through low swampy country for nearly eighty miles with varied terrain including damp plains, peaty soil, shallow lakes, and reed beds.

Darwin reaches the fifth posta, passing the site of a previous Indian massacre, noting the exposed position and successful hunting activities of stationed soldiers.

Darwin describes the elegant gait of the long-legged plover and the teru-tero bird, its sharp wing spurs, vocal habits that alarm other animals, and esteemed eggs.

Darwin reports that enormous hail fell and killed numerous wild animals including deer and ostriches, supporting this account with corroborating evidence from other naturalists.

Darwin describes the low quartz hills of Sierra Tapalguen with flat table-land formations surrounded by perpendicular cliffs, noting an unusual corral formation used by Indians.

Darwin discovers he was eating puma rather than calf, noting its white meat resembles veal in both appearance and taste, and verifies this assessment against Dr. Shaw's observations.

Darwin observes the Indian settlement of Tapalguen with numerous toldos and small Spanish shops, noting the handsome appearance of young Indians and availability of trade goods.

Darwin reflects on his experience eating only meat for several days and compares Gaucho dietary practices, noting their consumption of large proportions of fat and ability to abstain from food.

Darwin notes the pretty patterns and brilliant colors of woven items made by Indian women, with craftsmanship so fine it was mistaken for English manufacture.

Darwin describes a difficult ride through water-logged country and arrival at Rio Salado, a deep stream that becomes saltier in summer, staying at General Rosas's fortified estate.

Darwin observes a dramatic change in vegetation after crossing Salado, from coarse herbage to fine green carpet, attributing this to cattle grazing and manuring effects.

Darwin notes the extraordinary spread of European plants like fennel and especially cardoon, which now covers hundreds of square miles and prevents other vegetation from growing.

Darwin applies Lyell's principles to argue that introduction of domestic animals and European plants has dramatically altered South American ecology, eliminating native species and introducing new ones.

Darwin notes intense public enthusiasm for General Rosas and his wars against Indians, described as justified against barbarians who previously threatened all life.

Darwin arrives at Buenos Aires, praising its regular grid layout and architectural qualities, and noting its one-story hollow-square houses with central courtyards.

Darwin describes the dramatic spectacle of the cattle corral where horsemen lasso and drag cattle using the mechanical advantage of their mount's superior positioning, culminating in brutal slaughter.