In vital economy, the search-light of science has found the protoplasm which from our present state of knowledge seems to be the first point of contact between elemental matter and the vital force. What secrets of biology remain unknown within the realm of life, only those who live in the future may ever know. In the first condition of vitalised matter we find the evidence of autonomy. Whatever may be the ultimate force which actuates this monad, the manifestations of its presence and the result of its energy are seen externally. Whatever may be the nature of that force which imparts motion to matter, the first impulse of the biod is to secure food or to associate itself with a unit of its own kind. This is perhaps the first act of volition within the sphere of life, the first expression of some internal want, and is the first faint suggestion of a consciousness, however feeble; and I may add with propriety, that it is my opinion that the vital and psychic forces operate in a manner not unlike the electric and chemical forces. They appear to polarise, and in this condition act on matter in harmony with that great law of Nature under which positive repels positive and attracts negative, and _vice versâ_. We shall not attempt to follow the tedious steps of progress from inanimate matter to man, but begin with those intermediate forms which are so far developed as to utter sounds and understand the sounds of others. We will deal only with tangible facts as we find them. From whatever source expression may arise, or at whatever point it may appear, it is prompted by desire or some kindred emotion, either positive or negative. [Sidenote: MODES OF EXPRESSION]