From the genetic standpoint it is otherwise. It regards the multiplicity of instincts as issuing out of relative unity, the primitive libido. It recognizes that definite quantities of the primitive libido are split off, associated with the recently created functions, and finally merged in them. From this standpoint we can say, without any difficulty, that patients with dementia præcox withdraw their “libido” from the external world and in consequence suffer a loss of reality, which is compensated by an increase of the phantasy-building activities. We must now fit the new conception of libido into that theory of sexuality in childhood which is of such great importance in the theory of neurosis. Generally speaking, we first find the libido as the energy of vital activities acting in the zone of the function of nutrition. Through the rhythmical movements in the act of sucking, nourishment is taken with all signs of satisfaction. As the individual grows and his organs develop, the libido creates new ways of desire, new activities and satisfactions. Now the original model—rhythmic activity, creating pleasure and satisfaction—must be transferred to other functions which have their final goal in sexuality. This transition is not made suddenly at puberty, but it takes place gradually throughout the course of the greater part of childhood. The libido can only very slowly and with great difficulty detach itself from the characteristics of the function of nutrition, in order to pass over into the characteristics of sexual function. As far as I can see, we have two epochs during this transition, the epoch of _sucking_ and the epoch of the _displaced rhythmic activity_. Considered solely from the point of view of its mode of action, sucking clings entirely to the domain of the function of nutrition, but it presents also a far wider aspect, it is no mere function of nutrition, it is a rhythmical activity, with its goal in a pleasure and satisfaction of its own, distinct from the obtaining of nourishment. The hand comes into play as an accessory organ. In the epoch of the displaced rhythmical activity it stands out still more as an accessory organ, when the oral zone ceases to give pleasure, which must now be obtained in other directions. The possibilities are many. As a rule the other openings of the body become the first objects of interest of the libido; then follow the skin in general and certain places of predilection upon it.