excitement is bound to entirely different mechanical conditions. After the second system has finished its tentative mental work, it removes the inhibition and congestion of the excitements and allows these excitements to flow off to the motility.

An interesting train of thought now presents itself if we consider the relations of this inhibition of discharge by the second system to the regulation through the principle of pain.

Let us now seek the counterpart of the primary feeling of gratification, namely, the objective feeling of fear. A perceptive stimulus acts on the primitive apparatus, becoming the source of a painful emotion. This will then be followed by irregular motor manifestations until one of these withdraws the apparatus from perception and at the same time from pain, but on