It distributes blood to most of the organs of the body. If the gut is transected near the clitellum and lifted, the ventral blood vessel will be seen running beneath the gut. The reproductive system consists of conspicuous and inconspicuous parts. Remember the earthworm is monoecious. By carefully removing the gut and circulatory system up to segment 5, the full extent of these organs may be seen.
Testes are small and buried in the bottom of the vesicles.
They will not be visible. Tiny, conical ovaries hang, near the midline, from the anterior septum of segment 13 and the egg funnel and egg sac are in the posterior septum of the same segment. All specimens may not show these organs well. An oviduct leads from each egg sac to the openings seen on segment 14. Locate the tiny brain, a two-lobed mass, on the dorsal surface of the pharynx.