Let us stick to experience. Physiology teaches that generation is a "prolonged nutrition," a surplus, as we see so plainly in the lower forms of agamous generation (budding, division). The creative imagination likewise presupposes a superabundance of psychic life that might otherwise spend itself in another way. Generation in the physical order is a spontaneous, natural tendency, although it may be stimulated, successfully or otherwise, by artificial means. We can say as much of the other. This list of resemblances it would be easy to prolong. But all this is insufficient for the establishment of a thorough identity between the two cases and the solution of the question. It is possible to limit it, to put it into more precise language. Is there a connection between the development of the generative function and that of the imagination? Even in this form the question scarcely permits any but vague answers. In favor of a connection we may allege: (1) The well-known influence of puberty on the imagination of both sexes, expressing itself in day-dreams, in aspirations toward an unattainable ideal,[28] in the genius for invention that love bestows upon the least favored. Let us recall also the mental troubles, the psychoses designated by the name hebephrenia. With adolescence coincides the first flowering of the fancy which, having emerged from its swaddling-clothes of childhood, is not yet sophisticated and rationalized. It is not a matter of indifference for the general thesis of the present work to note that this development of the imagination depends wholly on the first effervescence of the emotional life. That "influence of the feelings on the imagination" and of "the imagination on the feelings" of which the moralists and the older psychologists speak so often is a vague formula for expressing this fact--that the motor element included in the images is reinforced. (2) _Per contra_, the weakening of the generative power and of the constructive imagination coincide in old age, which is, in a word, a decay of nutrition, a progressive atrophy. It is proper not to omit the influence of castration. According to the theory of Brown-Sequard, it produces an abatement of the nutritive functions through the suppression of an internal stimulus; and, although its relations to the imagination have not been especially studied, it is not rash to admit that it is an arresting cause.