n. (Zool.) One of a peculiar kind of internal buds, or germs, produced in the interior of certain Bryozoa and sponges, especially in the fresh- water species; - also called winter buds. They are protected by a firm covering, and are usually destined to perpetuate the species during the winter season. They burst open and develop in the spring. In some fresh-water sponges they serve to preserve the species during the dry season.