Syphacia muris, the Rat Pinworm.
A migration of gravid Syphacia muris pinworms down the large intestine of the rat host is shown to occur from the seventh day on in the worm's life cycle. Eggs obtained from migrating worms have proved to be infective to helminth-free rats after incubation in saline for 30 minutes at room temperature and 4 hours at 37 degrees C.
Stahl
W
W