. Mammals of other lands;. Mammals. CHAPTER XXII MARSUPIALS AND MONOTREMES BY W. SAVILLE-KENT, , MARSUPIALS WITH the order of the Pouched Mammals we arrive — with the exception of the Echidna and Platypus, next described — at the most simply organised representatives of the Mammalian Class. In the two forms above named, egg-production, after the manner of birds and reptiles, constitutes the only method of propagation. Although among marsupials so rudimentary a method of reproduction is not met with, the young are brought into the world in a far more embryonic condition than occurs
. Mammals of other lands;. Mammals. CHAPTER XXII MARSUPIALS AND MONOTREMES BY W. SAVILLE-KENT, , MARSUPIALS WITH the order of the Pouched Mammals we arrive — with the exception of the Echidna and Platypus, next described — at the most simply organised representatives of the Mammalian Class. In the two forms above named, egg-production, after the manner of birds and reptiles, constitutes the only method of propagation. Although among marsupials so rudimentary a method of reproduction is not met with, the young are brought into the world in a far more embryonic condition than occurs among any of the mammalian groups previously enumerated. There is, as a matter of fact.'an entire absence of that vascular or blood connection betwixt the parent and young previous to birth, known as 'placentation, common to all the higher mammals, though certain of the more generalised forms have been recently found to possess a rudiment of such development. In correlation with their abnormally premature birth, it may be observed that a special provision commonly exists for the early nurture of the infant marsupials. In such a form as the Kangaroo, for example, the young one is placed, through the instrumentality of its parent's lips, in contact with the food-supplying teat, and to which for some considerable period it then becomes inseparably attached. Special muscles exist in connection with the parent's mammary glands for controlling the supply of milk to the young animal, while the respiratory organs of the little creature are temporarily modified in order to ensure unimpeded respiration. The fact of the young in their early life being commonly found thus inseparably adhering to the parent's nipple has given rise to the fallacious but still very widely prevalent idea among the Australian settlers that the embryo marsupial is ushered into the world as a direct outgrowth from the mammary region. At the present day, with the exception of the small group of the American O
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Keywords: ., bookauthorco, bookcentury1900, bookdecade1910, booksubjectmammals
