Abstract
The normal niche of T. spiralis adults is in the epithelial layer of the mucosa of the small intestine of its host [mouse]. Most worms were found in the epithelium at the base of the villi and in the glandular crypts. Copulation and insemination occurred 30-32 h postinfection, and although these acts were never observed, copulation and insemination apparently took place in the epithelial layer of the mucosa. Most adults were completely embedded in the epithelium during the deposition of the motile larvae. Motile larvae were deposited in this location and from there migrated through the stroma to venules and lymphatic vessels. Male T. spiralis were capable of inseminating at least 4 females.