As we advance in the scale of life, we are met with constantly increasing unfoldment of mentation, the simple giving place to the complex manifestations. Passing by the simple vital processes of the monera, or single-celled "things," we notice the higher forms of cell life, with growing sensibility or sensation. Then we come to the cell-groups, in which the individual cells manifest sensation of a kind, coupled with a community-sensation. Food is distinguished, selected and captured, and movements exercised in pursuit of the same. The living thing is beginning to manifest more complex mental states. Then the stage of the lower plants is reached, and we notice the varied phenomena of that region, evidencing an increased sensitiveness, although there are practically no signs of special organs of sense. Then we pass on to the higher plant life, in which begin to manifest certain "sensitive-cells," or groups of such cells, which are rudimentary sense organs. Then the forms of animal life, and considered with rising degrees of sensations and growing sense apparatus, or sense organs, gradually unfolding into something like nervous systems. Among the lower animal forms there are varying degrees of mentation with accompanying nerve centers and sense-organs, but little or no signs of consciousness, gradually ascending until we have dawning consciousness in the reptile kingdom, etc., and fuller consciousness and a degree of intelligent thought in the still higher forms, gradually increasing until we reach the plane of the highest mammals, such as the horse, dog, elephant, ape, etc., which animals have complex nervous systems, brains and well developed consciousness. We need not further consider the forms of mentation in the forms of life below the Conscious stage, for that would carry us far from our subject.