It would be giving a very false idea of the interests which stirred Charles Darwin's mind during his long five years' voyage, however, if we were to dwell exclusively upon the biological side of his numerous observations on that memorable cruise. Ethnology, geology, oceanic phenomena, the height of the snow-line, the climate of the Antarctic islands, the formation of icebergs, the transport of boulders, the habits and manners engendered by slavery, all almost equally aroused in their own way the young naturalist's vivid interest. Nowhere do we get the faintest trace of narrow specialism; nowhere are we cramped within the restricted horizon of the mere vulgar beetle-hunter and butterfly-catcher. The biologist of the 'Beagle' had taken the whole world of science for his special province. Darwin's mind with all its vastness was not, indeed, profoundly analytical. The task of working out the psychological and metaphysical aspects of evolution fell rather to the great organising and systematising intellect of Herbert Spencer. But within the realm of material fact, and of the widest possible inferences based upon such fact, Darwin's keen and comprehensive spirit ranged freely over the whole illimitable field of nature. 'No one,' says Buckle with unwonted felicity, 'can have a firm grasp of any science if, by confining himself to it, he shuts out the light of analogy. He may, no doubt, work at the details of his subject; he may be useful in adding to its facts; he will never be able to enlarge its philosophy. For the philosophy of every department depends on its connection with other departments, and must therefore be sought at their points of contact. It must be looked for in the place where they touch and coalesce: it lies, not in the centre of each science, but on the confines and margin.' This profound truth Darwin fully and instinctively realised. It was the all-embracing catholicity of his manifold interests that raised him into the greatest pure biologist of all time, and that enabled him to co-ordinate with such splendid results the raw data of so many distinct and separate sciences. And even as early as the days of the cruise in the 'Beagle,' that innate catholicity had already asserted itself in full vigour. Now it is a party of Gauchos throwing the bola that engages for the moment his eager attention; and now again it is a group of shivering Fuegians, standing naked with their long hair streaming in the wind on a snowy promontory of their barren coast. Here he examines the tubular lightning-holes melted in the solid rock of Maldonado by the electric energy; and there he observes the moving boulder-streams that course like torrents down the rugged corries of the Falkland Islands. At one time he works upon the unstudied geology of the South American Pampas; at another, he inspects the now classical lagoon and narrow fringing reef of the Keeling archipelago. Everywhere he sees whatever of