The purely physical phenomena of life, to be rightly appreciated, must always be considered in relation to the psychical phenomena which are the soul of life. These subtle and intangible forces cannot be experimented with in the laboratory, or expressed in formulæ; we cannot denote their strength in horse-power. Just as the physical manifestations of life begin with lowly types, so the psychical begin, and they gather strength and complexity with the bodies they pervade. These manifestations we call behaviour, and in their more intense developments, “emotions.” These emotions present an infinite range of variety in the higher animals, and they attain their maximum of intensity wherever the reproductive activities are concerned. The part which these activities play in controlling behaviour is by no means always apparent, and is commonly not even suspected. Even man himself is subject to this control. And it is this fact which lifts the “Courtship” of the lower animals out of the category of merely curious phenomena. For the springs of his conduct, his behaviour and “emotions” under varying circumstances, can only be understood, and even then but imperfectly, by comparison with other creatures lower in the scale, so far, of course, as comparison is possible. This line of inquiry, then, takes one back to the simplest living things, among which there is neither marrying nor giving in marriage, neither birth nor death. Life is reduced to its simplest terms—a speck of animated jelly is all that confronts one, and this is only to be seen under a high power of the microscope. It has neither mouth nor organs of digestion, no visible means of locomotion are traceable, and the special senses of sight and hearing are wanting; but taste and smell, of a nebulous kind, are there. Shape it cannot be said to have, for its bodily outline is constantly changing, thereby it moves. A long tongue of its jelly-like substance, or “protoplasm” as it is called, is thrust forwards, and the rest of the body is, as it were, dragged after it. Whatever animal, or vegetable, matter it passes over, in the course of its wanderings, is drawn up into the semi-fluid substance of this diaphanous body, and its juices extracted, the undigestible residue is left behind in the course of the morning’s walk! In due time it becomes adult; further growth is impossible. When this stage is attained a strange thing happens. A certain minute, more solid portion of this body, which lies in the very centre of the mass and is known as the “nucleus,” begins to assume an hour-glass shape. Speedily the constriction becomes apparent across the whole body and rapidly increasing, cuts it in two, as if by the tightening of some invisible thread. Here Death is cheated, and records of births are unknown! And just as there are no parents so there are no children. But a foreshadowing of what is to be occurs even here. For every now and then two individuals, to all appearances identical, meet and