Résumé : The emission of hyperfragments and the formation of cryptofragments following the absorption at rest of Σ- hyperons in emulsion nuclei have been studied. Both these phenomena appear to occur less frequently than in the case of K- mesons absorptions. From of a study of short prongs and Auger electrons it is suggested that hyperfragments are emitted predominantly from light nuclei, while cryptofragments are formed preferentially in heavy nuclei. © 1962 Società Italiana di Fisica.