A Study on the Structure of Egg Shell of Enterobius Vermicularis (Linnaeus, 1758) Leach, 1853, with the Electron Microscope

1. The shell of the ova of Enterobius vermicularis is composed of two chitinous layers, a compact outer layer and a looser inner layer. Both surfaces of the two layers have a dense border. 2. The outer layer has innumerable tubules about 0.2 micron in diameter, and only those tubules found in the thinner part of the layer open to the outside and inside. 3. The outer layer of mature eggs is about 0.45 micron and the inner layer about 2 to 6 microns, in thickness. 4. The chitinous microfibrils in both layers form a rcticular structure which contains very fine granules in the mesh.