[Succcus nerveus and succus seminalis in Borelli's living machine].

: Analogy between testicles and brain is an ancient one, and it has often taken the form of an analogy between semen and 'succus nerveus' (a liquid substance produced by the brain and circulating in the nerves). The paper deals with an Early Modern version of the analogy, outlined by Giovanni Alfonso Borelli in his De motu animalium (1680-81). Elements from the medical tradition of Antiquity and Renaissance can be traced in Borelli's system, together with the effort towards the creation of a mechanico-chemical model of the machine of the living organism. Nervous and seminal fluids are supposed to animate and perfect the machine.