| Germ Layers | Specialized tissue, can generated after worm is cut in half |
| Differentiation | complex tissue-origins |
| Circular Muscles | thicken and shorten muscles as they contract, attach setae to soil as a grip for movement |
| Longitudinal Muscles | contract and pull worm forward and elongates |
| Coelom | fluid filled structure against which muscles contact, allowing movement for organs, providing nutrients and transport of wastes |
| Circulatory system | Dorsal blood vessel act like a heart, taking oxygenated blood from capillaries, pumps blood doing peristalsis, has a total of 10 hearts |
| Nephridospore | Acts like kidneys eliminating liquid toxins |
| Digestive Track (1) | Mouth moistens food, sucks into pharynx |
| Digestive Track (2) | Food moved to esophagus |
| Digestive Track (3) | Food stored in crop |
| Digestive Track (4) | Ground up in gizzards when ready for processing |
| Digestive Track (5) | Enters long intestine lined with typholsole, enzymes secreted, nutrients enter blood stream |
| Digestive Track (6) | Food exits through anus; casting (fertilizing pellets) |
| Typholsole | Cells that increase surface area |
| Nervous System | Brain in anterior end is mass of nerve cells (ganglia), 1 longitudinal nerve cord runs length of body. Septum divides into compartments and nerve cord branched out connecting to each segment |
| Reproductive System | Dual sex organs, can't fertilize its own eggs, 2 testes, sperm in seminal vesicles |
| Earthworm Sexual Orientation | Hermaphrodites |
| Mating Process (1) | Face opposite, slide along each other lining up gonopores |
| Mating Process (2) | Citellum secretes mucus, each worm deposits sperm into other through mucus film. Once completed worms separate |
| Mating Process (3) | Citellum becomes cocoon where eggs are incubated 2-3 weeks, hatched out in soil |