Evidence of the origin of the gelatinous masses in the oviducts of mares

The gelatinous masses known to occur in the mare oviduct were examined by light and scanning electron microscopy. Many (44%) of the masses which occurred in 16 of the 24 oviducts studied were connected with the mucosa of the ampulla near the ampullary-isthmic junction. The masses consisted of lobules of fine fibres probably derived from the fibrous connective tissue of the lamina propria in the oviductal mucosa.