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The Effects Of Penicillin Upon The Fission Rate Of Dugesia Dorotocephala., John J. Fahsbender

Theses and Dissertations

Planaria (class Turbellaria) are the highest life forms which exhibit fission (Hyman, 1951). The laboratory planarian, Dugesia, lives in lakes, ponds, streams and springs, where it occupies bottom habitats. Fissioning is an asexual mode of reproduction. The fission plane is usually transverse, forming behind the pharynx, and separation appears to be dependent upon locomotion (Curtis, 1902). The posterior half of the worm adheres to the substratum while the anterior half continues to move forward until the worm snaps in two. Each half then regenerates the missing parts, forming two new smaller worms.