Thomas Henry Huxley; A Sketch Of His Life And Work. Sir P. Chalmers Mitchell

into the relationship which he thought had formerly subsisted between them. She was immediately acknowledged by the whole tribe as one of themselves, thus securing an extensive connection in relatives of all denominations. The headquarters of the tribe being on an island which all vessels passing through the Torres Strait from the eastward must approach within two or three miles, she had the mortification of seeing from twenty to thirty or more ships go through every summer without anchoring in the neighbourhood, so as to afford the slightest opportunity of making her escape. Last year she heard of our two vessels being at Cape York, only twenty miles distant from some of the tribe who had communicated with us and had been well treated, but they would not take her over and watched her even more narrowly than before. On our second and present visit, however, which the Cape York people immediately announced by smoke signals to their friends, she was successful in persuading some of her more immediate friends to bring her across to the mainland within a short distance of where the vessels lay. The blacks were credulous enough to believe that as she had been so long with them and had been so well treated, she did not intend to leave them—only 'she felt a strong desire to see the white people once more and shake hands with them': adding that she would be certain to purchase some axes, knives, tobacco, and other much-prized articles."

      Although the external adventures of the Rattlesnake party were less varied and exciting than might have been expected in a voyage of four years in the tropic seas and among barbarian tribes, the mental adventures through which Huxley passed in the time must have been of the most surprising kind. It was a four-years' course in the great university of nature, and when he had finished it he was no longer a mere student, capricious and unsettled in his mental tastes and inclinations, but had set his face steadily towards his future life-work. It is interesting to compare the importance in Huxley's life of the Rattlesnake voyage with the importance in Darwin's life of the voyage on the Beagle undertaken some fifteen years earlier. Huxley, when he started, was a young surgeon with a taste of a vague kind for dissecting and for drawing the peculiarities of structure of different animals revealed by the knife and the microscope. Day after day, month after month, year after year, in the abundant leisure his slight professional duties left him, he dissected and drew, dissected and drew, animal after animal, as he got them from the dredge or tow-net, or from the surface of the coral reefs. He was not in any sense of the word a collecting naturalist. The identification and naming of species interested him little. What he cared for was, he tells us, "the architectural and engineering part of the business: the working out of the wonderful unity of plan in the thousands and thousands of divers living constructions, and the modifications of similar apparatuses to serve different ends." And so, on the Rattlesnake, and in his work in continuation of the Rattlesnake investigations—which occupied most of his time for a few years after his return to London—there was gradually growing up in his mind a dim conception of the animal kingdom as a group of creatures, not built on half a dozen or more separate plans or types, each unconnected with the other, but as a varied set of modifications of a single type.

      When Darwin set out on the Beagle, unlike Huxley, he was an enthusiastic collecting naturalist. He had wandered from county to county in England adding new specimens to his collections of butterflies and beetles. As the Beagle went round the world visiting remote islands, far from land in the centre of the waters, archipelagoes of islands crowding together, islands hugging the shore of continents, and the great continents of the old and new worlds, he continued to collect and to classify. Gradually the resemblances and differences between the creatures inhabiting different parts of the earth began to strike him as exhibiting an orderly plan. He saw that under apparently the same conditions of food and temperature and moisture, in different parts of the world the genera and species were different, and that they were most alike in regions between which there was the most recent chance of migrations having taken place. In the quietness of England, while Huxley was on the Rattlesnake, Darwin was slowly working towards the explanation of all he had seen: towards the conception that animals and plants had spread slowly from common centres, becoming more and more different from each other as they spread. He realised on his voyage that species had come into existence by descent with modification, and before long he was to publish to the world in the Origin of Species a vast and convincing bulk of evidence as to the actual fact of a common descent for all the different existing organisms, and, in his theory of natural selection, a reasonable explanation of how the fact of evolution had come about. Darwin's greatest ally in bringing the new idea before the world was Huxley, and Huxley was teaching himself the absolute unity of the living world. The two men were dissimilar in tastes and temperament, and they were at work on quite different sides of nature. When the time came, Huxley, with his commanding knowledge of the structure of animals, was ready to support Darwin and to illustrate and amplify his arguments by a thousand anatomical proofs. It is a curious and dramatic coincidence to realise that both men learned their very different lessons under very similar circumstances in the tropical seas of the Southern Hemisphere.

      FOOTNOTES:

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      [B] Narrative of the Voyage of H.M.S. "Rattlesnake," by John MacGillivray, F.R.G.S. 2 vols. T.W. Boone, London, 1852.

[C] This sketch was reproduced and described in Natural Science, vol. vii., p. 381, and is now reproduced here by the courtesy of the proprietors.

[Contents]

CHAPTER III

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FLOATING CREATURES OF THE SEA

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      The Nature of Floating Life—Memoir on Medusæ Accepted by the Royal Society—Old and New Ideas of the Animal Kingdom—What Huxley Discovered in Medusæ—His Comparison of them with Vertebrate Embryos.

      As the Rattlesnake sailed through the tropical seas Huxley came in contact with the very peculiar and interesting inhabitants of the surface of the sea, known now to naturalists as pelagic life or "plankton." Although a poet has spoken of the "unvintageable sea," all parts of the ocean surface teem with life. Sometimes, as in high latitudes, the cold is so great that only the simplest microscopic forms are able to maintain existence. In the tropics, animals and plants are abundant, and sometimes by their numbers colour great areas of water; or, as in the drift of the Gulf Stream, make a tangle of animal and plant life through which a boat travels only with difficulty. The basis of the food supply of this vast and hungry floating life is, as on land, vegetable life; for plants are the only creatures capable of building up food from the gases of the air and the simple chemical salts found dissolved in water. Occasionally, in shallow or warm seas, marine floating plants, large and visible like the sea-weeds of the coast, form the floating masses known as Sargasso seas; more often the plants are minute, microscopic specks visible only when a drop of water is placed under the microscope, but occurring in incredible numbers, and, like the green vegetation of the earth, forming the ultimate food-supply of all the living things around them. Innumerable animals, great and small, live on the plants or upon their fellows, and, however far he may be from land, the naturalist has always abundant material got by his daily use of the tow-net. This drifting population floats at the mercy of the waves. Most of the animals are delicate, transparent creatures, their transparency helping to protect them from the attacks of hungry