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by Charles Darwin The original, squashed down to read in about 25 minutes  (London, 1839) Darwin's researches with the Royal Navy survey ship 'Beagle' laid the foundations of his "Origin of Species." Abridged: JH I.--To the South American Coast After having been twice driven back by heavy south-west gales, H.M.S. Beagle, a ten-gun brig, under the command of Captain Fitzroy, R.N., sailed from Devonport on December 27, 1831. The object of the expedition was to complete the survey of Patagonia and Tierra del Fuego, commenced under Captain King in 1826-30; to survey the shores of Chile, Peru, and of some of the islands in the Pacific; and to carry a chain of chronometrical measurements round the world. On January 16, 1832, we touched at Porto Praya, St. Jago, in the Cape de Verde archipelago, and sailed thence to Rio de Janeiro, Brazil. Delight is a weak term to express the higher feelings of wonder, astonishment, and devotion which fill the mind of a naturalist in wandering through the Brazilian tropical forest. The noise from the insects is so loud that it may be heard at sea several hundred yards from the shore, yet within the recesses of the forest a universal silence seems to reign. The wonderful and beautiful flowering parasites invariably struck me as the most novel object in these grand scenes. Among the cabbage-palms, waving their elegant heads fifty feet from the ground, were woody creepers, two feet in circumference, themselves covered by other creepers. The humming birds are fond of shady spots, and these little creatures, with their brilliant plumage, buzzing round the flowers with wings vibrating so rapidly as scarcely to be visible, seek the tiny insects in the calyx rather than the fabled honey. Insects are particularly numerous, the bees excepted. The Beagle was employed surveying the extreme southern and eastern coasts of America south of the Plata during the two succeeding years. The almost entire absence of trees in the pampas of Uruguay, the provinces of Buenos Ayres [now Argentina], and Patagonia is remarkable. Fifteen miles from the Rio Negro, the principal river on the whole line of coast between the Strait of Magellan and the Plata, are several shallow lakes of brine in winter, which in summer are converted into fields of snow-white salt two and a half miles long and one broad. The border of the lakes is formed of mud, which is thrown up by a kind of worm. How surprising it is that any creature should be able to exist in brine, and that they should be crawling among crystals of sulphate of soda and lime! The valley of the Rio Negro, broad as it is, has merely been excavated out of the sandstone plain; and everywhere the landscape wears the same sterile aspect. II.--Fossil Monsters of the Pampas The pampas are formed from the mud, gravel, and sand thrown up by the sea during the slow elevation of the land; and the section disclosed at Punta Alta, a few miles from Bahia Blanca, was interesting from the number and extraordinary character of the remains of gigantic land animals embedded in it. I also found remains of immense armadillo-like animals on the banks of a tributary of the Rio Negro; and, indeed, I believe that the whole area of the pampas is one wide sepulchre of these extinct colossal quadrupeds. The following, which I unearthed, are now deposited in the College of Surgeons, London. (1) Head and bones of a megatherium, the huge dimensions of which are expressed by its name; (2) the megalonyx, a great allied animal; (3) the perfect skeleton of a scelidorium, also an allied animal, as large as a rhinoceros, in structure like the Cape ant-eater, but in some other respects approaching the armadilloes; (4) the mylodon Darwinii, a closely related genus, and little inferior in size; (5) another gigantic dental quadruped; (6) another large animal very like an armadillo; (7) an extinct kind of horse (it is a marvellous fact in the history of the mammalia that, in South America, a native horse should have lived and disappeared, to be succeeded in after ages by the countless herds descended from the few introduced with the Spanish colonists); (8) a pachydermatous animal, a huge beast with a long neck like a camel; (9) the toxodon, perhaps the strangest animal ever discovered; in size it equalled an elephant, or megatherium, but was intimately related to the Gnawers, the order which at the present day includes most of the smallest quadrupeds; and judging from the position of the eyes, ears, and nostrils, it was probably aquatic. We have good evidence that these gigantic quadrupeds, more different from those of the present day than the oldest of the Tertiary quadrupeds of Europe, lived whilst the sea was peopled with most of its present inhabitants. These animals migrated on land, since submerged, near Behring's Strait, from Siberia into North America, and thence on land, since submerged, in the West Indies into South America, where they mingled with the forms characteristic of that southern continent, and have since become extinct. The existing animals of the pampas include the puma, the South American lion, while the birds are numerous. The largest is the ostrich, which is found in groups. The ostriches are fleet in pace, prefer running against the wind, and freely take to the water. At first start they expand their wings, and, like a vessel, make all sail. Of mammalia, the jaguar, or South American tiger, is the most formidable. It frequents the wooded and reedy banks of the great rivers. There are four species of armadilloes, notable for their smooth, hard, defensive covering. Of reptiles there are many kinds. One snake, a trigonocephalus, has in some respects the structure of a viper with the habits of a rattlesnake. The expression of this snake's face is hideous and fierce. I do not think I ever saw anything more ugly, excepting, perhaps, some of the viper-bats. III.--In the Extreme South From the Rio Plata the course of the Beagle was directed to the mouth of the Santa Cruz river, on the coast of Patagonia. One evening, when we were about ten miles from the bay of San Blas, vast numbers of butterflies, in bands and flocks of countless myriads, extended as far as the eye could range. One dark night, with a fresh breeze, the foam and every part of the surface of the waves glowed with a pale light. The vessel drove before her bows two billows of liquid phosphorus, and in her wake she was followed by a milky train. I am inclined to consider that the phosphorescence is the result of organic particles, by which process (one is tempted almost to call it a kind of respiration) the ocean becomes purified. The geology of Patagonia is interesting. For hundreds of miles of coast there is one great deposit composed of shells--a white pumiceous stone like chalk, including gypsum and infusoria. At Port St. Julian it is eight hundred feet thick, and is capped by a mass of gravel forming probably one of the largest beds of shingle in the world, extending to the foot of the Cordilleras. For 1,200 miles from the Rio Plata to Tierra del Fuego the land has been raised by many hundred feet, and the uprising movement has been interrupted by at least eight long periods of rest, during which the sea ate deep back into the land, forming at successive levels the long lines of cliffs, or escarpments, which separate the different plains as they rise like steps one behind the other. What a history of geological change does the simply constructed coast of Patagonia reveal! In some red mud, capping the gravel, I discovered fossil bones which showed the wonderful relationship in the same continent between the dead and the living, and will, I have no doubt, hereafter throw more light on the appearance of organic beings on our earth and their disappearance from it than any other class of facts. Patagonia is sterile, but is possessed of a greater stock of rodents than any other country in the world. The principal animals are the llamas, in herds up to 500, and the puma, which, with the condor and other carrion hawks, preys upon them. From the Strait of Magellan, the Beagle twice made a compass of the Falkland Islands, and archipelago in nearly the same latitude. It is a delicate and wretched land, everywhere covered by a peaty soil and wiry grass of one monotonous colour. The only native quadruped is a large wolf-like fox, which will soon be as extinct as the dodo. The birds embrace enormous numbers of sea-fowl, especially geese and penguins. The wings of a great logger-headed duck called the "steamer" are too weak for flight; but, by their aid, partly by swimming, partly flapping, they move very quickly. Thus we found in South America three birds who use their wings for other purposes besides flight--the penguins as fins, the "steamers" as paddles, and the ostrich as sails. Tierra del Fuego may be described as a mountainous land, separated from the South American continent by the Strait of Magellan, partly submerged in the sea, so that deep inlets and bays occupy the place where valleys should exist. The mountain-sides, except on the exposed western coasts, are covered from the water's edge upwards to the perpetual snow-line by one great forest, chiefly of beeches. Viewing the stunted natives on the west coast, one can hardly conceive that they are fellow-creatures and inhabitants of the same world; and I believe that in this extreme part of South America man exists in a lower state of improvement than in any other part of the globe. The zoology of Tierra del Fuego is very poor. In the gloomy woods there are few birds, but where flowers grow there are humming birds, a few parrots and insects, but no reptiles. IV.--The Wonders of the Cordilleras After encountering many adventures in these Antarctic seas, among which was a narrow escape from shipwreck in a fierce gale off Cape Horn, and amidst hitherto unexplored Antarctic islands, the Beagle set a course northward in the open Pacific for Valparaiso, the chief seaport of Chile, which was reached on July 23, 1834. Chile is a narrow strip of land between the Cordilleras and the Pacific, and this strip itself is traversed by many mountain lines which run parallel to the great range. Between these outer lines and the main Cordilleras a succession of level basins, generally opening into each other by narrow passages, extend far to the southward. These basins, no doubt, are the bottoms of ancient inlets and deep bays such as at the present day intersect every part of Tierra del Fuego. From November, 1834, to March, 1835, the Beagle was employed in surveying the island of Chiloe and the broken line called the Chonos Archipelago. This archipelago is covered by one dense forest, resembling that of Tierra del Fuego, but incomparably more beautiful. There are few parts of the world within the temperate regions where so much rain falls. The winds are very boisterous, and the sky almost always clouded. Fortunately, for once, while we were on the east side of Chiloe the day rose splendidly clear, and we could see the great range of the Andes on the mainland with three active volcanoes, each 7,000 feet high. While at Valdivia, on the mainland, on February 20, 1835, the worst earthquake ever recorded in Chile occurred, and it was followed for twelve days by no less than 300 tremblings. A bad earthquake at once destroys our oldest associations; the earth, the very emblem of solidity, has moved beneath our feet like a thin crust over a fluid. One second of time has created in the mind a strange idea of insecurity which hours of reflection would not have produced. The most remarkable effect was the permanent elevation of the land round the Bay of Concepcion by several feet. The convulsion was more effectual in lessening the size of the island of Quiriquina off the coast than the ordinary wear and tear of the sea and weather during the course of a whole century; but on the other hand, on the Island of St. Maria putrid mussel-shells, still adhering to the rocks, were found ten feet above high-water mark. Near Juan Fernandez Island a volcano uprose from under the water close to the shore, and at the same instant two volcanoes in the far-off Cordilleras bust forth into action. The space from which volcanic matter was actually erupted is 720 miles in one line and 400 miles in another line at right-angles from the first; hence, in all probability, a subterranean lake of lava is here stretched out of nearly double the area of the Black Sea. The frequent quakings of the earth on this line of coast are caused, I believe, by the rending of the strata, necessarily consequent on the tension of the land when upraised, and their injection by fluidified rock. This rending and injection would, if repeated often enough, form a chain of hills. I made the passage of the Cordilleras to Mendoza, the capital of the republic of that name, on horseback. The features in the scenery of the Andes which struck me most were that all the main valleys have on both sides a fringe, sometimes expanding into a narrow plain of shingle and sand. I am convinced that these shingle terraces were accumulated during the gradual elevation of the Cordilleras by the torrents delivering at successive levels their detritus on the beach-heads of long, narrow arms of the sea, first high up the valleys, then lower down and lower down as the land slowly rose. If this be so, and I cannot doubt it, the grand and broken chain of the Cordilleras, instead of having been suddenly thrown up--as was till lately the universal, and still is the common, opinion of geologists--has been slowly upheaved in mass in the same gradual manner as the coasts of the Atlantic and Pacific have arisen within the recent period. The other striking features of the Cordilleras were the bright colours, chiefly red and purple, of the utterly bare and precipitous hills of porphyry; the grand and continuous wall-like dikes; the plainly divided strata, which, where nearly vertical, formed the picturesque and wild central pinnacles, but where less inclined composed the great massive mountains on the outskirts of the range; and lastly, the smooth, conical piles of fine and brightly-coloured detritus, which slope up sometimes to a height of more than 2,000 feet. It is an old story, but not less wonderful, to see shells which were once crawling at the bottom of the sea now standing nearly 14,000 feet above its level. But there must have been a subsidence of several thousand feet as well as the ensuing elevation. Daily it is forced home on the mind of the geologist that nothing, not even the wind that blows, is so unstable as the level of the crust of the earth. From Valparaiso to Coquimbo, and thence to Copiapo, in Northern Chile, the country is singularly broken and barren. On some of the terraced plains rising to the Cordilleras, covered with cacti, there were large herds of llamas. At one point in the coast range great prostrate silicified trunks of fir trees were very numerous, embedded in a conglomerate. I discovered convincing proof that this part of the continent of South America has been elevated near the coast from 400 feet to 1,300 feet since the epoch of existing shells; and further inland the rise possibly may have been greater. From the evidence of ruins of Indian villages at very great altitude, now absolutely barren, and some fossil human relics, man must have inhabited South America for an immensely long period. From the port of Iquique, in Peru, a visit was made across the desert to the nitrate of soda mines. The nitrate stratum, between two and three feet thick, lies close to the surface, and follows for 150 miles the margin of the plain. From the troubled state of the country, I saw very little of the rest of Peru. A month was spent in the Galapagos Archipelago--a group of volcanic islands situated on the Equator between 500 and 600 miles westward of the coast of America. The little archipelago is a little world within itself. Hence, both in time and space, we seemed to be brought somewhere near to that great fact, that mystery of mysteries, the first appearance of new beings on this earth. The vegetation is scanty. The principal animals are the giant tortoises, so large that it requires six or eight men to lift one. The most remarkable feature of the natural history of this archipelago is that the different islands are inhabited by different kinds of tortoises; and so with the birds, insects, and plants. One is astonished at the amount of creative force, if such an expression may be used, displayed on these small, barren, and rocky islands, and still more so at its diverse, yet analogous, action on points so near each other. V.--The Coral Islands of the Indian Ocean Having completed the survey of the coasts and islands of the South American continent, the Beagle sailed across the wide Pacific to Tahiti, New Zealand, and Australia, in order to carry out the chain of chronometrical measurements round the world. From Australasia a run was then made for Keeling or Cocos Island in the Indian Ocean. This lonely island, 600 miles from the coast of Sumatra, is an atoll, or lagoon island. The land is entirely composed of fragments of coral. There is, to my mind, much grandeur in the view of the outer shores of these lagoon islands. The ocean, throwing its waters over the broad barrier-like reef, appears an invincible, all-powerful enemy. Yet these low, insignificant coral islets stand and are victorious; for here another power, as an antagonist, takes part in the contest. Organic forces separate the atoms of carbonate of lime, one by one, from the foaming breakers, and unite them in a symmetrical structure. Let the hurricane tear up its thousand huge fragments, yet what will that tell against the accumulated labour of myriads of architects at work night and day, month after month? There are three great classes of coral reefs--atoll, barrier, and fringing. Now, the utmost depth at which corals can construct reefs is between twenty and thirty fathoms, so that wherever there is an atoll a foundation must have originally existed within a depth of from twenty to thirty fathoms from the surface. The coral formation is raised only to that height to which the waves can throw up fragments and the winds pile up sand. The foundation, such as a mountain peak, therefore, must have sunk to the required level, and not have been raised, as has hitherto been generally supposed. I venture, therefore, to affirm that, on the theory of the upward growth of the corals during the sinking of the land, all the leading features of those wonderful structures, the lagoon-islands or atolls, as well as the no less wonderful barrier-reefs, whether encircling small islands, or stretching for hundreds of miles along the shores of a continent, are simply explained. On the other hand, coasts merely fringed by reefs cannot have subsided to any perceptible amount, and therefore they must, since the growth of their corals, either have remained stationary or have been upheaved. The chronometrical measurements were completed in the Indian Ocean by a visit to Mauritius, and thence, voyaging around the Cape of Good Hope, to the islands of St. Helena and Ascension, in the Southern Atlantic, and to the mainland of Brazil at Bahia and Pernambuco, from which the course was set for home. The Beagle made the shores of England at Falmouth on October 2, 1836, after an absence of nearly five years. On a retrospect, among the scenes which are deeply impressed on my mind, including the spectacles of the Southern Cross, the Cloud of Magellan, and the other constellations of the Southern Hemisphere, the glacier leading its blue stream of ice overhanging the sea in a bold precipice, the lagoon-islands raised by the reef-building corals, the active volcano, the overwhelming effects of a violent earthquake--none exceed in sublimity the primeval forests undefaced by the hand of man, whether those of Brazil, where the powers of Life are predominant, or those of Tierra del Fuego, where Death and Decay prevail. Both are temples filled with the varied productions of the God of nature. No one can stand in those solitudes unmoved and not feel that there is more in man than the mere breath of his body. And so with the boundless plains of Patagonia, or when looking from the highest crest of the Cordilleras, the mind is filled with the stupendous dimensions of the surrounding masses. |
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