A MORPHOLOGICAL AND ULTRASTRUCTURAL-STUDY OF THE PARACLOACAL (SCENT) GLANDS OF THE MARSUPIAL METACHIRUS-NUDICAUDATUS GEOFFROY, 1803

Morphological and ultrastructural features of the paracloacal glands o f Metachirus us nudicaudatus are described. Two pairs of glands, one o n the right and the other on the left of the anal canal, are formed, e ach consisting of a major and a minor portion. Their wall is made up o f three layers: a mucosal, a muscular and an external capsule. The inn er one is a mucosa the epithelium of which contains holocrine cells ch aracterized by lipid droplets and intermediate filaments. The surround ing vascular lamina propria contains flattened tubular apocrine glands whose epithelial cells contain abundant endoplasmic reticulum, promin ent Golgi complexes and numerous secretory granules. The middle layer is formed by skeletal striated muscle and the outer (third layer) cons ists of dense connective tissue. Each gland originates from a single d uct. Transverse sections show that each duct, except in the female maj or gland, is in fact formed by a duct system. One of these ducts comes from the central cavity, lined by holocrine epithelium, and the other s result from the branched tubular glands of the lamina propria.