The evolution of man- a popular exposition of the principal points of human ontogeny and phylogeny. From the German of Ernst Haeckel (1897) (14781673235)

Didelphis marsupialis syn. D. cancrivora syn. Philander cancrivorus
Identifier: evolutionofmanpo021897haec (find matches)
Title: The evolution of man: a popular exposition of the principal points of human ontogeny and phylogeny. From the German of Ernst Haeckel
Year: 1897 (1890s)
Authors: Haeckel, Ernst Heinrich Philipp August, 1834-1919
Subjects: Evolution Embryology, Human Anatomy, Comparative Human beings -- Origin Embryology Evolution
Publisher: New York, D. Appleton and Co.
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library



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thesimple structure of the allantois (which does not as yetdevelop a placenta), with many other characters, have beeninherited by the Pouched Animals from Cloacal Animals.On the other hand, they have lost the independent coracoidbone (os coracoideuim) attached to the shoulder girdle. Amore important step consists in the fact that a cloaca is nolonger formed ; the cavity of the rectum, together with theanal opening, is separated by a partition wall from the urinaryand sexual opening (sinus urogenitalis). Moreover, allPouched Animals develop special nipples on the milk-glands,which are sucked by the young after birth. These nipplesproject into the cavity of a pouch, or marsupium, in theventral side of the mother. This pouch is supported bya couple of marsujaal bones. In it the young, which are 152 THE EVOLUTION OF MAN born in a very imperfect condition, are carried by themother foi a long time; until, in fact, they are completelydevelopiid (Fig. 197). In the large Giant Kangaroo, which
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Fig. 197.—The Crab-eating Pouched Eat (Philander cancrivorus). Afemale with two yoang in its pouch. (After Brehm.) THE POUCHED ANIMALS AS ANCESTORS OF MAN. 153 attains the height of a man, the embryo develops in theuterus but for a month; it is then born in a very incompletecondition, and attains all its fuither development in tliemother s pouch, where, for about nine months, it remainsattached to the milk-olands. All these and other characters especially the peculiarstructure of the internal and external sexual organs of themale and female) clearly show that the whole sub-class ofthe Pouched Animals (Marsupialia) are a single group,which originated from the promammalian branch. From abranch of these Pouched Animals (perhaps from severalbranches) the parent-forms of the higher Mammals, thePlacental Animals, afterw^ards sprang. Hence we mustreckon a whole series of Pouched Animals among the an-cestors of the human race; and these constitute the seven-teenth stage in tlie human pedigr