Observations on the laternal vaginae and birth canals in the marsupials Isoodon macrourus and Perameles nasuta (Mammalia)

The laternal vaginae in the bandicoots Isoodon macrourus and Perameles nasuta wer long, straight and tabular, and consisted of a mascular sheath, an intermediate connective tissue layer and a luminal epithelium. The muscle layer had an inwardly projecting longitudinal ridge in I. macrourus but not in P. nasuta . In both species, a glassy layer was present immediately below the epithelium which was usually stratified columnar in type, although a non-keratinzing squamous type occured in small regions in some P. nasuta during pregnancy. The distance between the lateral vaginae in the birth canal region increased during pregnancy and reached a maximum at birth. The birth canal lacked an epithelial lining and was patent in some animals for more than half the lactation period. The allantoic stalks were often retained within the birth canal region throughout the lactation period and in some animals during the next pregnancy and even during the early part of the subsequent lactation