In December 1961 W. W. SNELL was able to observe an ayahuasca ceremony among the Matsigenka ). This took place in a house in the Paratoari settlement on the River Manu. Since the Matsigenka had been visited and described in earlier decades principally by Dominican priests and since, for obvious reasons, these priests had little opportunity to attend shamanistic sessions, direct and indirect observations and descriptions of such sessions have remained the exception even till today.