And if in the inorganic world we find food for such considerations, with immensely greater instance are they forced upon us by a study of the organic. Here we enter a new realm of mystery, for the laws we encounter actively energizing at every point, are altogether different from those with which hitherto we have had to deal. The matter which enters into the constitution of living things,--animals or plants--is precisely the same as that of which the inorganic world is constituted. No single atom or molecule is found in the one which has not been drawn from the other;--nor when incorporated in a living structure do atoms or molecules suffer any alteration, or change their nature in any respect, for, says Clerk-Maxwell,[126] throughout all changes and catastrophes these remain "unbroken and unworn." Nevertheless, they fall at once under the spell of a force which introduces into their operations an order altogether new, for it somehow strikes across all the laws of dead matter, setting up a new code of its own, which endures just so long as life lasts, and is never met with apart from life. And these organic laws issue in marvellous results. Professor Haeckel himself, after endeavouring to show that from the inorganic world no arguments can be drawn to favour the supposition of design in Nature, thus continues:[127] But the idea of design has a very great significance and application in the _organic_ world. We do undeniably perceive a purpose in the structure and in the life of an organism. The plant and animal seem to be controlled by a definite design in the combination of their several parts, just as clearly as we see in the machines which man invents and constructs; as long as life continues, the functions of the several organs are directed to definite ends, just as is the operation of the various parts of a machine.