Het Leven der Dieren: Deel 1, Hoofdstuk 14: Buideldieren; Hoofdstuk 15: Kloakdieren

A descriptive survey of marsupial mammals outlines their distinctive reproductive anatomy, the presence and variation of a pouch and its supporting bones, and their unusually early birth of undeveloped young that continue growth while attached to a teat. The account highlights wide morphological diversity across families, from carnivorous to herbivorous habits and from terrestrial to arboreal and semiaquatic lifestyles, and emphasizes comparatively simple dental and locomotor structures versus other mammals. Geographic distribution, chiefly in Australia and parts of the Americas, and behavioral tendencies such as limited social attachment and variable maternal care are also examined.