Stimuli of the contact ceptors differ from stimuli of the distance ceptors in still another important particular. The adequacy of stimuli of the contact ceptors depends upon their number and intensity, while the adequacy of the stimuli of the distance ceptors depends upon the EXPERIENCE of the species and of the individual. That is, according to phylogeny and ontogeny this or that sound, this or that smell, this or that sight, through association recapitulates the experience of the species and of the individual-- awakens the phylogenetic and ontogenetic memory. In other words, sights, sounds, and odors are symbols which awaken phylogenetic association. If a species has become adapted to make a specific response to a certain object, then that response will occur automatically in an individual of that species when he hears, sees, or smells that object. Suppose, for example, that the shadow of a hawk were to fall simultaneously on the eyes of a bird, a rabbit, a cow, and a boy. That shadow would at once activate the rabbit and the bird to an endeavor to escape, each in a specific manner according to its phylogenetic adaptation; the cow would be indifferent and neutral; while the boy, according to his personal experience or ontogeny, might remain neutral, might watch the flight of the hawk with interest or might try to shoot it. Each phylogenetic and each ontogenetic experience by an indirect method develops its own mechanism of adaptation in the brain; and the brain threshold is raised or lowered to stimuli by the strength and frequency of repetition of the experience. Thus through the innumerable symbols supplied by environment the distance ceptors drive this or that animal according to the type of brain pattern and the particular state of threshold which has been developed in that animal by its phylogenetic and ontogenetic experiences. The brain pattern depends upon his phylogeny, the state of threshold upon his ontogeny. Each BRAIN PATTERN is created by some particular element in the environment to which an adaptation has been made for the good of the species. The _*state of threshold_ depends upon the effect made upon the individual by his personal contacts with that particular element in his environment. The presence of that element produces in the individual an associative recall of the adaptation of his species--that is, the brain pattern developed by his phylogeny becomes energized to make a specific response. The intensity of the response depends upon the state of threshold-- that is, upon the associative recall of the individual's own experience--his ontogeny.