recognized in an ideal construction which lets drop all concrete differences. The Life is different when the organism is different. Hence any definition of Life would be manifestly insufficient which while it expressed the activities of the Monad left unexpressed the conspicuous and important activities of higher organisms. A sundial and a repeater will each record the successive positions of the sun in the heavens; but although both are instruments for marking time, the sundial will not do the work of the repeater; the complexity and delicacy of the watch mechanism are necessary for its more varied and delicate uses. A semifluid bit of protoplasm will feed itself; but it will not feed and sustain a complex animal; nor will it feel and think.

9. Neglect of this point has caused frequent confusion in the attempts to give satisfactory definitions. Biologists ought to have been warned by the fact that some of the most widely accepted definitions exclude the most conspicuous phenomena of Life, and are only applicable to the vegetable world, or to the vegetal processes in the animal world. A definition, however abstract, should not exclude essential characters. The general consent of mankind has made Life synonymous with Mode of Existence. By the life of an animal is meant the existence of that animal; when dead the animal no longer exists; the substances of which the organism was composed exist, but under another mode; their connexus is altered, and the organism vanishes in the alteration. It is a serious mistake to call the corpse an organism; for that special combination which constituted the organism is not present in the corpse. This misconception misleads some speculative minds into assigning life to the universe. The universe assuredly exists, but it does not live; its existence can only be identified with life, such as we observe in organisms, by a complete obliteration of the speciality which the term

Life is meant to designate. Yet many have not only pleased themselves with such a conception, but have conceived the universe to be an organism fashioned, directed, and sustained by a soul like that of man - the anima mundi. This is to violate all scientific canons. The life of a plant-organism is not the same as the life of an animal-organism; the life of an animal-organism is not the same as the life of a human-organism; nor can the life of a human-organism be the same as the life of the worldorganism. The unity of Existences does not obliterate the variety of Modes; yet it is the speciality of each Mode which Science investigates; to some of these Modes the term Life is consistently applied, to others not; and if we merge them all in a common term, we must then invent a new term to designate the Modes now included under Life.

10. In resisting this unwarrantable extension of the term I am not only pointing to a speculative error, but also to a serious biological error common in both spiritualist and materialist schools, namely that of assigning Life to other than organic agencies. Instead of recognizing the speciality of this Mode of Existence as dependent on a speciality of the organic conditions, the spiritualist assigns Life to some extra-organic Vital Principle, the materialist assigns it to some inorganic agent — physical or chemical. Waiving for the present all discussion of Vitalism, let us consider in what sense we must separate organic from all inorganic phenomena.

11. There is a distinction between inorganic and organic which may fitly be called radical: it lies at the root of the phenomena, and must be accepted as an ultimate fact, although the synthesis on which it depends is analytically reducible to a complication of more primitive conditions. It has been already indicated in § 5. All organisms above the very simplest are syntheses of three terms: Structure,

Aliment, and Instrument. Crystals, like all other anorganisms have structure, and in a certain sense they may be said to grow (Mineralia crescunt), though the growth is by increase and not by modification: the motherlye, which is the food of the crystal, is never brought to the crystal, nor prepared for it, by any instrumental agency of the crystal. Organisms are exclusively instrumental; the organ is an instrument. The structural integrity of an organism is thus preserved through an alimentation which is effected through special instruments. Nothing like this is visible in anorganisms.

The increase of a crystal is further distinguishable from the growth of an organism, in the fact of its being simple. accretion without development; and the structure of the crystal is distinguishable from that of an organism in the fact that its integrity is preserved by the exclusion of all molecular change, and not by the simultaneous changes of molecular decomposition and recomposition. Inorganic substances are sometimes as unstable as organic, sometimes even more unstable; but their instability is the source of their structural destruction they change into other species; whereas the instability of organized substances (not of organic) is the source of their structural integrity the tissue is renovated, and its renovation is a consequence of its waste.

12. But while the distinction is thus radical, when we view the organism from the real — that is, from the synthetic point of view we must also urge the validity of

Crystals not only grow by assimilation, but even repair injuries, with a certain superficial resemblance to the repair of animal tissues. Thus, according to the experiments of JORDAN cited by Sir JAMES PAGET (Lectures on Surgical Pathology, I. 153, and 2d ed. p. 115), an octohedral crystal of alum, if fractured and replaced in a motherlye will in a few days exhibit a complete restoration of the original form. The whole crystal increases, but the increase is greatest on the broken edge, and the octohedral form is completely renewed. (Comp. § 113.)

the analytical point of view, which seizes on the conditions here complicated in a special group, and declares these conditions to be severally recognizable equally in anorganisms and in organisms. All the fundamental properties of Matter are recognizable in organized Matter. The elementary substances and forces familiar to physicists and chemists are the materials of the biologist; nor has there been found a single organic substance, however special, that is not reducible to inorganic elements. We see, then, that organized Matter is only a special combination of that which in other combinations presents chemical and physical phenomena; and we are prepared to find Chemistry and Physics indispensable aids in our analysis of organic phenomena. Aids, but only aids; indispensable, but insufficient.

13. There is therefore an ambiguity in the common statement that organized matter is not ordinary matter. Indisputable in one sense, this is eminently disputable when it is interpreted as evidence of a peculiar Vital Force "wholly unallied with the primary energy of Motion." If by "ordinary matter" be meant earths, crystals, gases, vapors, then assuredly organized matter is not ordinary. Between the living state of matter and its non-living state," says Dr. Beale," there is an absolute and irreconcilable difference; so far from our being able to demonstrate that the non-living passes by gradations into or gradually assumes the scale or condition of the living, the transition is sudden and abrupt, and matter already in the living state may pass into the non-living condition in the same sudden and complete manner."* The ambiguity here is sensible in the parallel case of the difference between crystallizable and coagulable matter, or between one crystal and another. If we can decompose the organic into

Cited by DRYSDALE, Life and the Equivalence of Force, Part II.

p. 149.

the inorganic, this shows that the elements of the one are elements of the other; and if we are not yet able to recompose the inorganic elements into organic matter (not at least in its more complex forms), may this not be due to the fact that we are ignorant of the proximate synthesis, ignorant of the precise way in which the elements are combined? I may have every individual part of a machine before me, but unless I know the proper position of each, I cannot with the parts reconstruct the machine. Indeed the very common argument on which so much stress is laid in favor of some mysterious Principle as the source of organic phenomena, namely, that human skill is hopelessly baffled in the attempt to make organic substances, still more a living cell, is futile. Men can make machines, it is said, but not organisms, ergo organisms must have a spiritual origin. But the fact is that no man can make a machine, unless he take advantage of the immense traditions of our race, and apply the skill of millions who have worked and thought before him, slowly and tentatively discovering the necessary means of mechanical effect. The greatest thinker, or the deepest scholar, who did not place himself in the line of the tradition, and learn the principles of mechanism, and the properties of the materials, would be as incapable of making a watch, as the physiologist now is of making a cell. But the skill of man has already succeeded in making many organic substances, and will perhaps eventually succeed in making a cell, certainly will, if ever the special synthesis which binds the elements together should be discovered. Not that such a discovery would alter the position of Biology in relation to Chemistry. The making of albumen, nay, the construction of an organism in the laboratory, would not in the least affect the foundation of Biology, would not obliterate the radical difference between organisms and anorganisms. It is the speciality of