sentinels, leaving his guide and horses behind, and ultimately reached Buenos Ayres in safety. After a fortnight's delay, Monte Video was once more made for. Here it appeared that the Beagle would remain sometime longer, so the restless inquirer started on another expedition, this time up the Uruguay and Rio Negro. One of the halts was at the house of a very large landed proprietor. A friend of the proprietor's, a runaway captain from Buenos Ayres, was very anxious to have the traveller's opinion on the beauty of the Buenos Ayres ladies, and on receiving satisfactory assurances, voluntarily gave up his bed to the stranger! During this journey amazing quantities of huge thistles were met with, the cardoon being as high as a horse's back, while the Pampas thistle rose above the rider's head. To leave the road for a yard was out of the question. Incidentally the writer describes fully the horsemanship of the Gauchos, and gives a vivid picture of the state of society in the towns.

During this journey, too, a peculiar breed of small cattle, called niata, was observed, but full details were not given till the second edition of the Journal appeared. This breed is strangely at a disadvantage in droughts, compared with ordinary cattle; their lower jaws project beyond the upper, and their lips do not join, rendering them unable to browse on twigs."This strikes me," says Darwin, "as a good illustration of how little we are able to judge from the ordinary habits of life, on what circumstances, occurring only at long intervals, the rarity or extinction of a species may be determined.”. By the time this appeared, however, in 1845, the author had embarked on his great investigation.

The Rio Plata was quitted on December 6, 1833, and sail was made for Port Desire, on the coast of Patagonia. One evening, ten miles from the Bay of San Blas, myriads of butterflies filled the air, so that the seamen cried out that it was snowing butterflies. The flight seemed to be voluntary. On another occasion many beetles were found alive and swimming, seventeen miles from the nearest land. But these instances were insignificant compared with the alighting of a large grasshopper on the Beagle, when to windward of the Cape de Verde Islands, and when the nearest land, in a direction not opposed to the prevailing trade wind, was 370 miles distant. Marvellous appearances of spiders far from land were also noted. One day when the ship was sixty miles from land vast numbers of a small gossamer spider arrived. Its habits in fact were aëronautic ; it would send forth a small thread, and suddenly letting go its hold, would sail away horizontally.

The Beagle arrived at Port Desire on December 23, 1833, but Patagonia afforded less of interest to the zoologist than the northern countries. The next halt was made at Port St. Julian, 110 miles further south, on January 9, 1834. Here the evidences of the modern elevation of Patagonia were powerfully reinforced, and further, from the nature of the animal remains arose the conviction that "existing animals have a close relation in form with extinct species," another of the germinal facts which bore fruit in the "Origin of Species." Darwin was led to speculate on the causes which could have extinguished so many great species, and he remarks most suggestively: "One is tempted to believe in such simple

relations as variation of climate and food, or introduction of enemies, or the increased numbers of other species, as the cause of the succession of races." But he does not yet go farther. He ends his reflections by observing: "All that at present can be said with certainty is that, as with the individual, so with the species, the hour of life has run its course, and is spent."

In the second edition of the Journal the philosopher showed signs of considerable advance (pp. 174-5). The effect of changed conditions is further developed. The checks to indefinite multiplication are insisted on, while the tendency of every species to increase geometrically is clearly pointed out. In the place of the former concluding sentence we find the following: "To admit that species generally become rare before they become extinct to feel no surprise at the comparative rarity of one species with another, and yet to call in some extraordinary agent and to marvel greatly when a species ceases to exist, appears to me much the same as to admit that sickness in the individual is the prelude to deathto feel no surprise at sickness-but when the sick man dies, to wonder, and to believe that he died through violence."

The continental regions of South America did not supply the sole food for the reflections of the young naturalist during this period. An intervening visit had been paid, in December, 1832, and January, 1833, to Tierra del Fuego, and the natives were most carefully observed. He was greatly struck by their low condition; one can hardly make oneself believe they are fellow creatures, and inhabitants of the same world." Yet

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these abject people have been infinitely raised since that period by missionaries, and Darwin, hearing of this success, which he termed wonderful, sent a donation to the South American Missionary Society.

The Falkland Islands were explored both in 1833 and 1834, and the Straits of Magellan were carefully examined, and many valuable geological facts recorded. The southern portion of the continent was at last quitted for Chili, Valparaiso being reached on July 23, 1834. After Tierra del Fuego this was a delightful change, and here Darwin found an old schoolfellow and friend, Mr. Richard Corfield, who entertained him hospitably during his stay in Chili. Various expeditions to the Andes, to Santiago, to gold mines and copper mines, supplied abundant objects of curiosity and science, as well as varied visions of beauty; but the fatigues undergone had to be paid for by a month's illness at Valparaiso, during which Mr. Corfield's kindness was unremitting.

The large island of Chiloe was visited in November, and its climate even in summer proved wretched, reminding one of some parts of the Hebrides, a week without torrents of rain being wonderful. Castro, the almost deserted Spanish capital, could not furnish, even. among hundreds of inhabitants, a pound of sugar or an ordinary knife. No one possessed either a watch or a clock, and the church bell was rung by guess by an old man who was supposed to have the best notion of time.

In December the rugged Chonos Archipelago, stilk further south, was explored. Here a storm worthy of Tierra del Fuego was experienced. "White, massive

clouds were piled up against a dark blue sky, and across them black, ragged sheets of vapour were rapidly driven. The successive mountain ranges appeared like dim shadows; and the setting sun cast on the woodland a yellow gleam, much like that produced by the flame of spirits of wine on a man's countenance. The water was white with the flying spray; and the wind lulled and roared again through the rigging. It was a most ominous, sublime scene." While near Tres Montes the year 1835 was ushered in, as Darwin says, "with the ceremonies proper to it in these regions. She lays out no false hopes; a heavy N.W. gale, with steady rain, bespeaks the rising year. Thank God, we are not destined here to see the end of it, but hope then to be in the Pacific, where a blue sky tells one there is a heavena something beyond the sky above our heads."

Valdivia being reached in February, the Beagle party were witnesses of a severe earthquake. Darwin was on shore, lying down in the wood to rest. The effect produced upon him by the motion he experienced was very marked: "There was no difficulty in standing upright, but the motion made me almost giddy. It was something like the movement of a vessel in a little cross ripple, or still more like that felt by a person skating over thin ice, which bends under the weight of his body. A bad earthquake at once destroys the oldest associations; the world, the very emblem of all that is solid, has moved. beneath our feet like a crust over a fluid; one second of time has conveyed to the mind a strange idea of insecurity, which hours of reflection would never have created." By the same earthquake every house in