This photo shows most of the major reproductive structure of the adult male, which are located at the posterior end of the body. At the top are two large, oval testes. The thin, dark duct at the posterior end of each testis is the vas efferens. The dark, elongate cluster near the posterior end is composed of six individual cement glands. A dark seminal vesicle is visible emerging from the posterior margin of the cement glands and curving around the oval cement reservoir. At the posterior end of the worm is an everted copulatory bursa.