[Gerontology and endocrinology at the beginning of the 20th century: Dr. Voronoff (1866-1951)].
Rejuvenation by monkey testicle transplanting was terribly fashionable in Paris, between years 1925-1930. The manual miracles done by a group of very well-known surgeons, in Paris, (especially Serge Voronoff and Dartigues) rooted in the head of a too credulous public the idea according to it was possible to be made scientifically younger by genital graftings. The "Etude sur la vieillesse et la rajeunissement par la greffe" (1926), written by Voronoff, provided the clinical, histological and iconographical proofs of a such rejuvenation. The paper analyses that was put forward as "proofs", situated in the scientific and cultural context of the time. A possible link between youth, sexual vigour and animality sends back to a mythic history of gerontology and endocrinology, two medical fields which however became scientific specialties in the beginning of the twentieth century.