Monoasters induced by taxol in the amoebae of the MyxomycetePhysarum polycephalum show an unusual tridimensional location of the centrioles. Tridimensional reconstructions of individual monoasters with either two or four centrioles show that the position of centrioles is not random. The characteristics of these monoasters suggest that the centrioles are not linked to the mitotic center in the monoaster since mitotic centers completely devoid of centrioles in adjacent or central location are observed. However, the preferential centrifugal orientation of the centrioles in the centrosphere induced by taxol suggests that centrioles are initially located in the mitotic center in agreement with the attachment of the centrioles to the mitotic center during interphase.