Using the work of Abraham Trembley as an example, the article describes how the modern biological laboratory was created by reconciling two previously indistinct forms and places: the experimental laboratory, concerned with hydra experiments, and the para-experimental laboratory, concerned with the preservation of laboratory animals. However, while all these practices were made public by Trembley when they left their place of production, only a few of his experiments were actually repeated, while the para-experimental dimension was set aside. In other words, the repetition of the experiments that ran through the show and led to the process of persuasion only touched on a small part of the actual laboratory work. This is why, for the sake of persuasion, the experimental laboratory was transformed into a public pseudo-laboratory when it crossed the boundaries of its original site. On the one hand, Trembley's articulation of experimental and para-experimental dimensions allows us to understand the emergence of the modern heuristic laboratory. On the other hand, beyond its boundaries, the laboratory gave rise to a multitude of delocalized pseudo-laboratories that organized spectacle and persuasion, making the distance between the public and the scientist appear similar to that between the producer and the consumer of knowledge.