The fine structure of adult Onchocerca volvulus. II. The intestine and the reproductive system of the male worm.

The morphology of the gut and the genital duct of five male worms from Liberia and two male worms at least five years old, from Upper Volta are described. The lumen of the intestine can be distended vesicularly or it can be reduced to a cleft which is filled with microvilli. The intestinal epithelium contains concentric spherules or dense bodies with piles of lamellae. In parts of the intestine of a live worm the cells can be completely disintegrated. The wall of the testis consists of a squamous epithelium which contains numerous dense bodies on the luminal side. The wall of the vas deferens is a squamous or cuboid epithelium which contains glycogen and various particles. In the ejaculatory duct the epithelial cells are linked together by desmosomes at their luminal side. The brownish appearance of some organs under the light microscope is related to the accumulation of iron containing particles.