FIELD AND FOREST. 1 57 



parent is provided with a muscle — cremaster — attached to each mar- 

 supial bone, and thence extending over the inner surface of the mam- 

 mae, by means of which the glands are compressed, injecting into the 

 mouths of the little ones the milk necessary for sustenance. As the 

 introduction of nourishment takes place through no voluntary act of 

 the young, but by that of the mother, many ask what provision has 

 been made to prevent the fluid entering the larynx, and thus suffo- 

 cating the little ones ? Nature has specially provided for this : the 

 larynx of the infant marsupial does not, as in other mammalia, open 

 at the base of the tongue and widely separate from the nostrils ; on 

 the contrary, it is prolonged into, and embraced by the nasal fossae. 

 By this conformation there is a free entrance of air from the nostrils 

 to the lungs by a passage entirely shut off from the mouth • at the same 

 time nourishment passes freely on either side of this prolonged wind- 

 pipe to the stomach. Thus breathing and feeding may go on simul- 

 taneously without either risk or inconvenience. 



As the young approach their more perfect form and development, 

 they loosen their hold, and frequently put out their heads from their 

 living cradle to survey the surrounding world. In time they leave 

 the pouch, though reserving it as a refuge from danger, or to make up 

 from the maternal fount for the insufficient nourishment which their 

 weak state has allowed them to procure elsewhere. With some of the 

 marsupials, it is not at all uncommon to find in the same pouch young 

 ones almost emancipated, and weak creatures of recent birth, adhering 

 to their respective mammae. 



The marsupium, or pouch, varies with different species. While with 

 some it is as complete as nature can devise, with others it consists of 

 but two folds of integument, obliging the mother to find other modes 

 of conveying her young from place to place. 



The living orders are remarkable for their divesity of structure and 

 habits, containing herbivorous, insectivorous, and carnivorous species. 

 The first of the group known to voyagers was the common opossum, 

 Didelphys Virginiana, which seems to combine a majority of the 

 characteristics and peculiarities of marsupials, and whose instinctive 

 care and cunning in protecting itself from its many enemies causes it 

 to so successfully counterfeit death as to give rise to the expression of 

 " playing possum," as a synonym of perfect deceit. 



As that wonderland, the great island continent of Australia, became 



