. Elementary text-book of zoology [electronic resource]. Zoology. MAMMALIA, 4S1 Phascolarctos it is normal and possibly performs its primary function of respiration. Recently, however, the discovery of an allantoic placenta in Pera7fieles has shown us that at least one metatherian has advanced to the foetal condition of the Eiitheria. The structure of this placenta would seem to have certain features which might indicate an independent evolution of the allantoic placenta within the The epipubic bones have the same relations as those of the Prototheria, and the exact significance of the
. Elementary text-book of zoology [electronic resource]. Zoology. MAMMALIA, 4S1 Phascolarctos it is normal and possibly performs its primary function of respiration. Recently, however, the discovery of an allantoic placenta in Pera7fieles has shown us that at least one metatherian has advanced to the foetal condition of the Eiitheria. The structure of this placenta would seem to have certain features which might indicate an independent evolution of the allantoic placenta within the The epipubic bones have the same relations as those of the Prototheria, and the exact significance of the tooth- succession is not yet decided. The known facts are as follows :— The majority of the Metatheria retain the one set of teeth throughout life, with the single exception of the third upper and lower tooth on each side behind the canine, hence termed the third pre-molar. This tooth usually resembles the teeth behind it rather than those in front, and at some time (earlier or later according to the species), it falls out and is replaced by a tooth growing down from above it. M. 32. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Masterman, Arthur Thomas; Parsons, John Herbert, Sir, 1868-1957, donor; S. H. Lazarus (Firm); University College, London. Library Services. Edinburgh : E. & S. Livingstone
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1901
