which led him to the conception of blood relationship between animals, and of the descent from a common original type.

The most famous of the opponents of Cuvier, and upholders of the doctrine of mutability of species, were two of his own countrymen, who were colleagues in Paris for many years, Lamarck and St. Hilaire.

LAMARCK, 1744-1829, was originally intended for the Church, like Linnæus, Cuvier, St. Hilaire, and Darwin. He, however, had a passion for the army, and on the death of his father in 1760 set off for Germany, where the French were then fighting. There he distinguished himself as a volunteer, but owing to being accidentally disabled by a comrade had to abandon his career. He then went to Paris, and commenced the study of medicine, while holding a post as a banker's clerk. He was for a long time interested in botany, and in 1779 published three small volumes on the Flora of France. This attracted the notice of Buffon, and in 1793 Lamarck obtained an appointment at the Jardin des Plantes, the year before Cuvier, and applied himself with great vigour to the study of zoology. Lamarck and Cuvier worked practically side by side for many years. Cuvier, working mainly at Vertebrates and at fossils, was impressed by the differences between species, especially those between recent and fossil species. Lamarck worked mainly at the lower Invertebrates-jelly-fish, worms, and snails. He, on the other hand, was struck by their resemblances rather than the differences between them, and was impressed by the difficulty of settling which were distinct species and which might have come from the same parents. On this point he observes: “The more we know of animals and plants, the more difficult we find it to settle which are related to each other and which are not."

Lamarck was also impressed by the variability of animals and plants, according to their surroundings, and by the influence of drier soil or mountain habitat in causing stunting of growth and other alterations. In his "Philosophie Zoologique,” published in 1809, and in the "Histoire Naturelle des Animaux sans Vertébres," published in 1815, he upholds the doctrine that all species of animals, including man, are descended from other species. With respect to the manner of modification, he attributes something to the direct action of environment, and much to use and disuse-i.e., to the effects of habit; for example, the use of the long neck of the giraffe for browsing on trees. He writes: "The systematic divisions of classes, orders, families, genera, and species are the arbitrary and artificial productions of man. Species arise out of varieties. In the first beginning only the very simplest and lowest animals and plants came into existence; those of a more complex organisation only at a later period. The course of the earth's development and that of its organic inhabitants was continuous, and not interrupted by violent revolutions. Life is purely a physical phenomenon." If man can make such changes in a few hundred years, as for example, to produce the various domestic races of pigeons or rabbits, "is it not possible that nature in all the long ages during which the world has existed may have produced the different kinds of plants and animals by gradually enlarging one part and diminishing another, to meet the wants of each?"

This is a full statement of all the essential points; the unity of active causes in organic and inorganic nature; the ultimate explanation of these causes in the chemical and physical properties of matter; the derivation of all organisms from some few most simple forms; the coherent course of events in Nature, and the absence of cataclysmal revolutions. It is a full and complete statement of the doctrine of Evolution as held at the present day, man himself being included, both as regards his mental powers and his bodily structure. This is often confused with the Darwinian theory, but is really quite distinct. Lamarck tells us that animals are descended one from another, and have a common bond of union or blood relationship. This explains the affinities of animals and of man, but fails to explain how and why. The Darwinian theory explains how this came about, and why this progressive transformation of organic forms has taken place, and what causes effected the uninterrupted production of new forms. Lamarck's views, though perfectly correct, were mere speculations until Darwin supplied the reason and explained the mode of action. Lamarck considered the long neck of the giraffe as due to its constantly stretching its neck to pick leaves from high trees; the long tongue of the woodpecker, humming-bird, and ant-eater to the

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habit of fetching food out of deep or narrow crevices; the webbed toes of the frog to its constant endeavours to swim, and to the very movements of swimming. The true explanation, as we shall see afterwards, was furnished by Darwin's theory of natural selection.

ST. HILAIRE, 1771-1840, was educated as a priest, but owing to his passionate love for zoology was allowed to stay in Paris and work at the Jardin des Plantes. He was offered an appointment, and afterwards joined Lamarck at the Musée d'Histoire Naturelle in 1793. St. Hilaire was a great friend of Lamarck, and adopted his theory of descent. He believed that the transformations of animals were effected less by the action of the organism itself, than by change in the outer environment. A long and fierce controversy raged between the three friends, Cuvier, Lamarck, and St. Hilaire, chiefly between Cuvier and St. Hilaire, who, strangely enough, was thought an abler man than Lamarck. Shortly after Lamarck's death a formal and final discussion took place in the Academy of Sciences at Paris between Cuvier and St. Hilaire. This occurred on the 22nd of February 1830, and was renewed on the 19th of July, a bare week before the outbreak of the French Revolution. All Europe was excited by the controversy, and none more so than Goethe, then an old man, and a firm believer in the doctrine of Evolution.

Cuvier was far too strong for his opponent; a hard hitter, and a man of greater personal power and influence, and one who did not scruple to use his full strength. He urged the evidence of mummies and other buried remains, which, after a lapse of thousands of years, agree in the smallest details with existing species. If a changing environment causes alterations, why, he asked, are these not altered? He demanded evidence of connecting links between fossils and recent forms, and quoted his own unrivalled experiences as to its absence. Cuvier crushed his opponent by superior knowledge, by the better management of his case, and by personal authority. The verdict was a definite one, and the controversy was regarded as closed by final decision. The fixity of species was regarded as proved, and France has hardly yet recovered from the traditions of Cuvier.

We now approach the final stage in the great controversy, and the scene of action shifts to our own country. Light was first afforded, not by zoology or botany, but by the sister science of geology, a peculiarly British study, and a very recent addition to the tree of knowledge.

HUTTON, 1726-1797, when sixty-two years old, published his "Theory of the Earth." The main motive of this book was to show that in order to understand how the earth's crust, with its component layers, was formed, and how fossils got into them, we must not guess, but must look for ourselves, and see what is now going on around us-how rivers and glaciers are carrying down earth and stones from the mountains to the sea, how the solid earth is being wasted every day, and new rocks formed by the disintegration of older ones.