The fine structure of adult Onchocerca volvulus IV. The hypodermal chords of the female worm.

The morphology of the hypodermal chords in the anterior, midbody and posterior region and in worms of different ages are described and the amphids, the cephalic papillae and the nerve ring are demonstrated. At the anterior end, the hypodermal cap comprises the sensory organs. Close behind, the hypodermal chords are differentiated, and several cell margins are found in all of them. Four sublateral chords are differentiated, and several cell margins are found in all of them. Four sublateral chords are also found in the anterior region. A row of median cells is found between the dorsal and ventral syncytia further behind and at the posterior end. In the midbody region, the lateral chords are very large but without central cells. Various particles and inclusions such as bacteria, dense bodies and fibrils are found in the plasm of the hypodermal chords. A large multilayered inclusion was found in the degenerating chord of a female worm at least five years old.