[The proventriculus of the Xenopsylla cheopis flea studied by scanning electron microscopy].

The proventriculus of the flea X. cheopis was studied by means of scanning electron microscopy. The external surface of the proventriculus is a rigid structure with an alveolate surface ("wasp nest") formed by muscular cords. The internal surface of the proventriculus is represented by numerous acanthae which fall close together. They have a shape of bent dens with longitudinal sharply angular edges and concave spaces between them. Some edges are crenate.