Read "Three Essays on the Theory of Sexuality" by Sigmund Freud online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
From the course of development as described we can clearly see the issue and the end aim. The intermediary transitions are still quite obscure and many a riddle will have to be solved in them.
The most striking process of puberty has been selected as its most characteristic; it is the manifest growth of the external genitals which have shown a relative inhibition of growth during the latency period of childhood. Simultaneously the inner genitals develop to such an extent as to be able to furnish sexual products or to receive them for the purpose of forming a new living being. A most complicated apparatus is thus formed which waits to be claimed.