. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. MARSUPIALIA. 327 ressity for such a structure, for he dissected ?wo small mammary foetuses of the Kangaroo for the especial purpose of showing the rela- tion of the larynx to the posterior nares. The epiglottis and arytenoid cartilages are elongated and approximated, and the rima glottidis is thus situated at the apex of a cone-shaped larynx, (Jig. 142, c,) which projects, as in the Cetacea, into the posterior nares, where it is closely embraced by the muscles of the soft palate. The air-passage (6) is thus completely se
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. MARSUPIALIA. 327 ressity for such a structure, for he dissected ?wo small mammary foetuses of the Kangaroo for the especial purpose of showing the rela- tion of the larynx to the posterior nares. The epiglottis and arytenoid cartilages are elongated and approximated, and the rima glottidis is thus situated at the apex of a cone-shaped larynx, (Jig. 142, c,) which projects, as in the Cetacea, into the posterior nares, where it is closely embraced by the muscles of the soft palate. The air-passage (6) is thus completely separated from the fauces, and the injected milk passes in a divided stream on either side the larynx to the oesophagus. Fig. Nipple, and head of Mammary Foetus, Kangaroo. Thus aided and protected by modifications of structure, both in the system of the mother and its own, designed with especial reference to each other's peculiar condition, and afford- ing, therefore, the most irrefragable evidence of creative foresight, the small offspring of the Kangaroo continues to increase, from suste- nance exclusively derived from the mother, for a period of about eight months. During this period the hind legs and tail assume a great part of their adult proportions; the muzzle elongates; the external ears and eyelids are completed ; the hair begins to be developed at about the sixth month. At the eighth month the young Kangaroo may be seen frequently to protrude its head from the mouth of the pouch, and to crop the grass at the same time that the mother is browsing. Having thus acquired additional strength, it quits the pouch and hops at first with a feeble and vacillating gait, but continues to return to the pouch for occasional shelter and supplies of food till it has attained the weight of ten pounds. After this it will occasionally insert its head for the pur- pose of sucking, notwithstanding another foetus may have been deposited in the pouch; for the latter, as we have seen, a
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