Chapter IX
Falkland Islands: Climate, fauna including wild cattle, climate change effects, and historical observations of the territory.
86 argumentative units
- 01Expedition framework and conditions
Darwin describes the organization and logistics of the boat expedition up the Santa Cruz River, including provisions, party size, and the systematic division of labor among crew members.
- 02Physical description of the Santa Cruz River
Darwin documents the river's size, depth, current velocity, water color, and the surrounding valley's dimensions and terraced formation.
- 03Observation of Patagonian uniformity
Darwin notes the striking similarity and sterility of Patagonian landscape and production, observing the same stunted plants, birds, and insects everywhere despite variations in specific locations.
- 04Fauna of Patagonia: rodents, foxes, and guanacos
Darwin describes the abundance of small rodents, their cannibalistic behavior, the small fox that preys on them, guanaco herds, and predation patterns of pumas and condors.
- 05Discovery of basaltic lava formations
Darwin documents the sudden appearance of basalt pebbles and then vast basaltic platforms, noting their increasing size and abundance along the river course.
- 06Claim about river inefficiency in transporting rock fragments
Darwin argues that despite the Santa Cruz's strong current, it moves only small rock fragments short distances, providing striking evidence of rivers' limited power of transport.
- 07Interpretation of basalt as submarine lava flows
Darwin argues that the basaltic formations are lava that flowed beneath the sea on a grand scale, with thickness increasing toward the Cordillera.
- 08Geological problem of valley formation
Darwin poses the question of what power could have removed such a massive thickness of hard basaltic rock over such a large area, challenging explanations by river erosion alone.
- 09Hypothesis that valley was formerly an arm of the sea
Darwin argues that evidence from step-formed terraces, valley expansion, and sea-shells indicates the valley was once occupied by a marine strait joining the Atlantic and Pacific.
- 10Explanation of basalt removal by tidal erosion
Darwin rejects catastrophic flood theories and instead proposes that tidal action, operating over vast timescales, gradually eroded and fragmented the basalt into smaller stones and mud.
- 11Landscape alteration at basalt formations
Darwin observes that the introduction of basaltic rock changes the character of the landscape, bringing new plants, water springs, and verdant patches unavailable in the sedimentary plains.
- 12Description and measurement of condor specimen
Darwin records the physical dimensions of a condor he shot and documents its wide geographical range across South America from the Strait of Magellan northward.
- 13Observation that condors require perpendicular cliffs
Darwin infers from the geographical distribution of condors that they depend on steep cliff formations for roosting and breeding.
- 14Account of condor reproduction and behavior
Darwin reports on condor nesting, egg-laying, fledgling period, and gregarious roosting behavior based on local accounts and his observations.
- 15Description of condor soaring and hunting patterns
Darwin describes how condors circle overhead, sometimes for pleasure and sometimes watching for dying animals or puma prey, and how Chilean shepherds train dogs to defend against them.
- 16Two methods for capturing condors in Chile
Darwin documents Chilean techniques for catching condors: either by fencing them in when gorged so they cannot take flight, or by noosing them at their roosting trees at night.
- 17Observations on condor behavior in captivity
Darwin reports on captive condors at Valparaiso, their feeding frequency, apparent health, and claims about their ability to survive weeks without food.
- 18Experimental test of condor olfactory abilities
Darwin describes his controlled experiment wrapping meat in paper near captive condors, finding they only reacted when the meat became visible, suggesting poor sense of smell.
- 19Review of conflicting evidence on vulture sense of smell
Darwin presents balanced evidence from anatomical studies, field observations, and controlled experiments, both supporting and contradicting acute olfaction in carrion-vultures.
- 20Argument that condors use vision at great altitude
Darwin argues that condors soaring at 3,000-4,000 feet altitude could easily spot animals below from distances of over two miles using superior eyesight while being unnoticed themselves.
- 21Detailed observation of condor soaring flight mechanics
Darwin describes the elegant mechanics of condor flight, noting the absence of wing flapping during gliding and explaining the aerodynamic principles of sustained soaring.
- 22Observation of erratic boulders in upper valley
Darwin documents massive angular erratic boulders found far from mountain sources and argues they must have been transported by floating icebergs.
- 23Discovery of Indian artifacts and signs
Darwin records evidence of Indian presence in the valley including horse tracks, weapon marks, and abandoned items suggesting recent passage through the region.
- 24Decision to end river expedition and return
Darwin describes Captain Fitz Roy's decision to halt the expedition at 140 miles from the Atlantic due to repetitive landscape, rapid river conditions, and dwindling provisions.
- 25Summary of expedition value and return journey
Darwin notes the rapid descent taking one day versus five days ascending, emphasizing the geological insights gained despite others' dissatisfaction with the expedition.
- 26Historical and geographical context of Falkland Islands
Darwin provides the political history of the Falklands, including French, Spanish, and British claims, and describes the current population as including many convicts and rebels.
- 27Description of Falkland Islands climate and landscape
Darwin characterizes the islands' bleak landscape of peaty soil and wiry grass, comparing the climate to high Welsh mountains but with more wind and rain.
- 28Organization of Falkland Islands excursion
Darwin describes setting out on horseback with two Gauchos to explore the island, noting harsh weather and the uniformity of the moorland landscape.
- 29Detailed account of wild cattle hunting method
Darwin provides an extended description of how the Gaucho St. Jago hunts a wild cow using bolas and lasso, including the horse's trained assistance and the final killing.
- 30Observation of wild bull behavior and strength
Darwin describes the impressive size and aggressive nature of wild bulls, noting that older bulls stand their ground and attack rather than flee.
- 31Account of Gaucho technique for subduing a bull
Darwin demonstrates how two Gauchos using paired lassos subdued a powerful bull by restraining its horns and hind legs, illustrating mastery of force through technique.
- 32Observation of wild horse limited range on islands
Darwin notes that wild horses, introduced by the French in 1764, remain confined to the eastern end of the island despite no natural barriers, attributed to local attachment.
- 33Investigation into factors checking wild horse increase
Darwin investigates why wild horse numbers increased more slowly than cattle, finding evidence that stallions force mares to abandon foals, causing higher mortality in horses.
- 34Observation of wild horse degeneration and physical changes
Darwin documents how wild horses have become smaller and weaker than imported stock, with irregular hoof growth causing lameness, and predicts future Falkland pony breeds.
- 35Description of wild cattle size, variation, and color distribution
Darwin reports that wild cattle appear to have increased in size unlike horses, and documents striking color variations in different regions of the island.
- 36Observation of color segregation in cattle herds
Darwin notes that cattle of different colors appear to remain segregated by location and that different colors calve at different times, suggesting incipient speciation.
- 37Account of successful rabbit introduction to Falklands
Darwin notes that rabbits, native to North Africa, surprisingly thrive in the damp Falkland climate despite limitation by geography and predators.
- 38Critique of French naturalists' rabbit species distinction
Darwin challenges the French classification of black rabbits as a distinct species, reporting that Gauchos confirm they breed freely with grey rabbits and produce mixed offspring.
- 39Description of unique Falkland wolf-like fox
Darwin establishes that the large wolf-like fox is endemic to the Falklands, found nowhere else in South America, making it a geographically isolated species.
- 40Account of Falkland fox tameness and curiosity
Darwin describes how the tame and curious behavior of Falkland foxes led sailors to flee rather than attack them, contrasting with their actual docility.
- 41Claim of fox uniqueness in isolated island geography
Darwin argues that the Falkland fox represents an unusual case of a large endemic mammal found only on a small, isolated island archipelago with no continental connection.
- 42Observation of fox population decline and future extinction
Darwin documents the rapid decrease of fox numbers and predicts they will soon be eradicated like the dodo as human settlement increases.
- 43Discovery of using bones as fuel in Falklands
Darwin reports that Gauchos use cattle bones as fuel, which burn nearly as hot as coals, and describes their winter practice of cleaning meat from bones for roasting.
- 44Observation of Falkland Islands lack of trees
Darwin notes the absence of trees on the islands despite forest coverage in nearby Tierra del Fuego, and describes the small shrubs and special fire-making techniques required.
- 45Observation of Gaucho muscular effort in riding
Darwin notes that even expert Gauchos experience stiffness after riding, revealing that their apparent ease masks significant muscular exertion.
- 46Description of wild cattle hunting with bolas
Darwin explains the systematic method of hunting wild cattle using multiple sets of bolas to entangle animals, then exhausting and driving them to settlements.
- 47Account of difficult final journey back to ship
Darwin describes the arduous ride back through swampy, rain-soaked terrain with repeated horse falls and crossing of difficult water obstacles.
- 48Overview of Falkland Islands geological structure
Darwin describes the simple geological composition of clay-slate, sandstone with fossils, and white quartz rock with symmetrically arched strata.
- 49Description of 'streams of stones' rock formations
Darwin documents the striking phenomenon of vast sheets and streams of angular quartz fragments covering valley bottoms, unchanged since ancient times.
- 50Observation of stone streams' remarkable flatness
Darwin notes the surprisingly gentle slopes of these stone streams, which would not impede a coach, and their coverage of hilltops and valleys.
- 51Interpretation of stone streams as evidence of convulsion
Darwin uses vivid analogies to describe the stone streams as evidence of past violent upheaval, likening them to solidified lava flows shattered by convulsion.
- 52Puzzle of inverted arched fragment on hilltop
Darwin poses a question about an inverted arched rock fragment on a hilltop, whether it was hurled airborne or indicates former higher elevation.
- 53Argument that violent event occurred after sea retreat
Darwin argues that the absence of rounded fragments and sand-filled crevices indicates the violent event occurred after the land rose above sea level.
- 54Explanation of fragment distribution by vibratory force
Darwin proposes that fragments were hurled from nearby slopes and then leveled into continuous sheets by vibrations from an overwhelming force.
- 55Analogy to 1835 Concepcion earthquake for scale
Darwin uses the 1835 Chilean earthquake to contextualize the enormous power required to move fragments 'like sand on a vibrating board.'
- 56Prediction of future scientific explanation for stone streams
Darwin acknowledges the mystery of the stone streams but expresses confidence that future scientific progress will explain it, as with erratic boulders.
- 57Brief overview of Falkland bird species
Darwin notes that water-fowl were formerly more abundant and describes various hawks, owls, and land-birds as less notable than the water-birds.
- 58Observation of cormorant playing with caught fish
Darwin describes a cormorant repeatedly releasing and retrieving a fish, comparing this to cat-mouse play and noting the cruelty of the behavior.
- 59Detailed observation of penguin land behavior
Darwin describes his interaction with a penguin defending its path to sea, noting its fighting spirit, head movement patterns, and renamed 'jackass penguin' from its braying call.
- 60Description of penguin movement on land and sea
Darwin explains that penguins use their wings as fins underwater but as front legs on land, moving quickly enough to resemble a quadruped.
- 61Account of upland goose species and behavior
Darwin describes the upland goose as common, non-migratory, breeding on small islets from fear of foxes, and herbivorous.
- 62Description of rock goose distribution and habitat
Darwin identifies the rock goose as living exclusively on sea beaches and found from Falklands to Chile, providing a landscape feature in Tierra del Fuego.
- 63Description of steamer duck physical and behavioral traits
Darwin describes the steamer duck's large size, inability to fly, and characteristic paddling-splashing motion that gave it its name.
- 64Observation of steamer duck wing movement mechanism
Darwin argues that steamer ducks move their wings alternately rather than together, a mechanism distinct from typical bird flight.
- 65Description of steamer duck noise and behavior
Darwin notes that steamer ducks make extraordinary noise and splashing comparable to bull-frogs, creating a curious auditory effect.
- 66Comparative analysis of South American wing-modified birds
Darwin compares three South American birds that use wings for non-flight purposes (penguin, steamer, ostrich) and references flightless birds from New Zealand.
- 67Description of steamer duck diving capability and diet
Darwin notes that steamer ducks dive only slightly and feed entirely on shellfish from rocks, requiring very strong heads and beaks.
- 68Observation of steamer ducks' evening communal display
Darwin describes steamer ducks gathering in evening flocks and making vocalizations similar to bull-frogs within the tropics.
- 69Introduction to observation of lower marine animals
Darwin notes that he made many observations on lower marine animals in Tierra del Fuego and Falklands but will focus only on zoophytes with moveable organs.
- 70Description of vulture-head organs on zoophyte cells
Darwin describes remarkable moveable organs resembling vulture heads attached to certain zoophytes, with varying mobility and structural details.
- 71Observation that vulture-head organs are independent of polypi
Darwin finds that immature polypi have perfect vulture-head organs, and these organs move independently of the polypi, suggesting a separate function.
- 72Observation of vulture-head size variation by cell position
Darwin notes that central cells have vulture-heads of only one-fourth the size of outer cells, indicating position-dependent variation.
- 73Description of varying movement patterns in vulture-heads
Darwin documents that vulture-head movements vary by species, from complete stillness to oscillating or rapid jerky motions at consistent rates.
- 74Observation of vulture-head response to touch
Darwin notes that touching a vulture-head with a needle causes it to grasp firmly enough to shake the entire branch.
- 75Hypothesis that vulture-heads serve branch support function
Darwin argues that vulture-head organs relate to the horny axis of branches rather than reproductive polypi, based on their formation and independence.
- 76Analogy of sea-pen appendage to tree roots
Darwin compares the fleshy appendage of sea-pens to tree roots, suggesting it serves the organism as a whole rather than individual polypi.
- 77Description of coordinated movement in another coralline
Darwin describes bristle-bearing cells in Crisia showing both independent and synchronized movement patterns across branches.
- 78Claim that coralline shows unified will despite multiple polypi
Darwin argues that coordinated movements in corallines demonstrate transmission of will through an organism of thousands of distinct polypi.
- 79Observation of phosphorescent light transmission in zoophyte
Darwin describes a zoophyte that glows phosphorescent green when rubbed, with light always traveling from base to extremities of branches.
- 80Expression of wonder at compound animal complexity
Darwin expresses fascination at how a plant-like body produces swimming eggs that develop into branched colonies of numerous distinct animals.
- 81Analogy of corallines to trees with buds as individuals
Darwin compares the union of polypi in corallines to buds in trees, both representing collections of individual organisms in common stock.
- 82Problem of defining individuality in colonial organisms
Darwin discusses how incomplete individuality in coralline polypi makes the concept of compound animals more striking than in trees with buds.
- 83Parallel to individuality through organism bisection examples
Darwin suggests that bisected organisms or natural divisions may illuminate how individuated organisms can form compound bodies.
- 84Explanation of polypi and buds as incomplete divisions
Darwin proposes that polypi in zoophytes and buds in trees represent cases where organism division has not been completely effected.
- 85Observation that budding creates tighter generational bonds
Darwin argues that propagation by buds creates closer relationships among individuals than reproduction by eggs or seeds.
- 86Claim that budded plants share common life duration
Darwin asserts that plants propagated by buds all share a common lifespan, and transmit peculiarities with certainty through grafts and layers.