We do not shrink from the most _reckless_ exploitation of those forests that have come down to us from the primeval past--the vast stores of coal buried deep in the bosom of the earth. The expert can now calculate with certainty that in a few hundred, at the very farthest in a thousand, years these stores will be exhausted. When it comes to this, the triumphant progress of industrial science will no doubt give us some substitute, perhaps even something better; but no technical knowledge, no science, can ever give us back anew those highly developed organisms of the plant and animal world which man to-day is recklessly sweeping out of the list of living things. They cannot restore to us the green woods and their animal life. We preserve with punctilious precision every vestige of the art of the past. The older the documents of earlier historic times are, the more eagerly they are coveted, the more highly they are valued. Our collectors gladly pay the largest sums for an old papyrus, an old picture, an object of decorative art, or a marble statue. And, as has been rightly remarked, what warrant have we that some new Phidias, some new Michael Angelo, some new Praxiteles will not arise, and give us something of as high value as these, or even much more perfect? Unreservedly to deny this would be the same thing as to give the lie to the progress of the human race. But the same man who, in this respect, acts so reverently, so conservatively, looks on with folded arms while treasures are destroyed that ought to be guarded with special affection and care, in these times when the great value of all natural science is so fully recognised.[16] We organise, at an extremely high cost, expeditions to survey and explore far-off regions. We sink into the greatest depths of the sea our cunningly devised trawl-nets, and study with ceaseless diligence the smallest organisms that they bring up into the light of day. We consider the course of the stars, and calculate with precision their remote orbits. We daily discover new secrets, and have almost ceased to feel surprised at each day bringing us something new, something yet unheard of. Much that is thus done to secure the treasures of the past _might equally well be done in coming years. But much that we neglect to do can never be made good_, for we are permitting the slaughter, up to the point of extinction, of the most remarkable, the most interesting, and the least known forms among the most highly organised of the creatures that dwell with us on our earth!