Insects

Pediculus humanus humanus. Egg ("nit") of body louse (unstained, scanning power). This is a typical egg attached to a hair shaft. Such eggs are large (0.8-1.0 mm long by 0.3 mm in breadth), oval, white, and crowned with a rounded cap or operculum provided with perforations through which the developing louse obtains air. The eggs are coated with a cementlike substance as they are laid onto hairs or fibers, which makes them strongly resistant to removal.