This wonderful play of the vital forces of nature is no less dependant on "conditions"--on the necessary pre-existing plasma, chemically balanced soils, organic solutions, etc.--than the alleged "dynamical aggregates," "_molecules organiques_," "plastide particles," or "highly differentiated life-stuff," insisted upon by the physicists, in their materialistic theories of life. These physicists make even the slightest change in developmental phases--whether statical, as in the case of crystals, or dynamical, as in the case of living organisms--to depend on physical conditions,--those aiding and abetting what they call the "molecular play of physical forces." But with their theory that matter and motion are the only self-subsistent, indestructible elements in the universe, what "molecular play" can be attributed to matter but that which is derived from motion, or some one of its alleged correlates? We can only imagine two sorts of motion as possible metaphysical conceptions in connection with matter--_molar_ motion, or that relating to matter moving in mass, and _molecular_ motion, or that relating to the movements of matter in its unaggregated form, or as confined to molecules. But motion itself is not an absolute entity. It is not so much even as a collocating or placing force of matter itself. It is, at best, only a mechanical impulse imparted by one moving body to another; or, more accurately speaking, a continuous change of place in a moving body. In other words, it is simply a _process_ or _mode_ of action, and stands in about the same relation to matter as _growth_ does to a living plant or tree. Independently of matter it has no existence, either objectively or subjectively, or even as a metaphysical conception. To allege its indestructibility, as the physicists do, is simply to predicate an additional property of indestructible matter. We may call it "force"--something that constantly expends itself in a moving body--but it is utterly incapable of definition, or of conception even, except as it stands related to such moving body. All the marvellous "correlates of motion," therefore, producing such wonderful effects upon matter, in both its molar and molecular states or conditions, are nothing more nor less than vague and inconclusive inductions, derived from premises having, at best, nothing but a relative existence in a universe of moving matter. It would be decidedly better to agree with Haeckel, that matter is the only actual existence, than to predicate of matter a co-existent and wholly inexplicable "somewhat," whereon to base a purely physical hypothesis of life.