1. Earthworm Dissection Lumbricus terrestris Kingdom: Animalia Phylum: Annelida

2. Before you start dissecting, find the following:
Mouth
Setae – the bristles used for locomotion. They are located by rubbing your fingers along the earthworm’s body. They are often times easier to feel than to see.
Sperm Duct
Clittelum

3. Mouth

4. Sperm Duct

5. Clittelum

6. Mouth
Pin your worm at the tip of the mouth and at its midpoint.

7. Continue your cut to the mouth
Start your incision 2 cm behind the clittelum.
Make sure not to cut too deeply.

8. Begin to separate the skin using pins

9. Pin the skin back as you go along the cut
Pin the skin back as you go along the cut. Angle your pins outward so that are out of the way.

10. As you pin the skin back, take your probe and break the partitions between the segments. These are called Septum.

12. Pharynx

13. Aortic Arches – Earthworms have 5 pair of these simple hearts.

14. Aortic Arch

15. Seminal Vesicles

16. Seminal Receptacles

17. Crop

18. Gizzard

19. Intestine
Dorsal Blood Vessel

20. Ventral Nerve Cord

21. Ventral Nerve Cord

22. Brain

23. Nerve Cord and Brain

24. Brain