Preen gland is an external skin gland. It is compound holocrine gland. It secretes an oily secretion. This oily fluid prevents the ducks from drying out its feathers as they are water birds. They do this by preening. This work deals with growth of the gland from the date of hatch to adult. It also deals with its gross anatomical and histological aspects of the gland in detail. This also form the basics of bird anatomy and for pathological studies