[Evolution of xenomas and the double role of polynuclear neutrophils in the microsporodiosis of Glugea stephani (Hagenmuller, 1899) in the flounder Platichthys flesus (Linne, 1758)].

Glugea stephani forms xenomas in the intestinal wall and in several organs of the flounder Platichthys flesus in the Languedoc's ponds. Four characteristic stages are recognised in the development of these xenomas: reinforcement of the wall and maintenance of the host-parasite equilibrium, inflammation, granulomaformation, cicatrisation. The role of the polymorph neutrophiles is essential, first because it harbours the sporoplasm and then because it contributes to the destruction of the spores. The entire phenomenon is described at the ultrastructure level.