The placenta occupies a remarkably varied position across the depth-psychological corpus, functioning simultaneously as a biological organ, a ritual symbol, a site of prenatal psychological transmission, and an image of primordial connection. Jung’s references are characteristically brief but charged: in active-imagination material cited in his Letters, a creature ‘in the shape of a child’ emerges from ‘a white placenta,’ suggesting the organ’s role as threshold between unconscious potentiality and formed psychic life, and in the index to Symbols of Transformation the ‘primitive idea of’ the placenta is noted without extended elaboration, pointing toward its ethnological resonance. Grof’s perinatal matrix research provides the most systematic treatment, situating the placenta within the physiology of intrauterine experience and noting its species-specific structure in discussions of LSD teratogenicity. Maté extends the biological argument into developmental psychopathology, tracking how cortisol transmission through the placenta during maternal stress shapes dopaminergic architecture and addiction vulnerability. Eliade locates placental symbolism within initiatory obstetric imagery — the caul, the amnion, the act of birth — as paradigms of second birth. Estes coins the evocative phrase ‘spiritual placenta’ to name the living mythological inheritance from which displaced or colonized peoples are severed. Porges situates placental reproduction in the deep evolutionary history of oxytocin and mammalian social engagement. The term thus traverses the biological, the archetypal, the cultural-political, and the perinatal-experiential registers, making it a genuinely multivalent node in the corpus.