the point of exhaustion, proved incapable of bringing about a cessation of the desire and consequently of securing the pleasure connected with gratification.

Thus there was required a second activity — in our terminology the activity of a second system — which should not permit the memory occupation to advance to perception and therefrom to restrict the psychic forces, but should lead the excitement emanating from the craving stimulus by a devious path over the spontaneous motility which ultimately should so change the outer world as to allow the real perception of the object of gratification to take place. Thus far we have elaborated the plan of the psychic apparatus; these two systems are the germ of the Unc. and Forec, which we include in the fully developed apparatus.