The genito-urinary system in monotremes and marsupials / by William Colin MacKenzie ; assisted by William J. Owen.

  • William Colin Mackenzie
Date:
1919
Catalogue details

Licence: In copyright

Credit: The genito-urinary system in monotremes and marsupials / by William Colin MacKenzie ; assisted by William J. Owen. Source: Wellcome Collection.

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    .5 cm. At its distal extremity a well-defined clitoris is noted. This latter is tongue-shaped, .5 cm. long and .25 cm. in width, showing a median ridge and a depression on each side. An interesting feature about the repro- ductive organs of the Tasmanian Devil is the development of the external genitalia towards a higher mammalian type, i.e., the separation of the urino-genital from the intestinal tract. In other Marsupials, e.g., Koala and Trichosurus, both these tracts open into a common vestibule or cloaca guarded by a common sphincter, so that these are truly monotrematous. In Trichosurus, however, the genito- urinary outlet is nearer the surface than the intestinal. In the Tasmanian Devil no cloaca can be said to exist. Ventral to, and distinct from, the intestinal orifice, and seen from the surface, is a labial projection corresponding to the termination of the urogenital canal. At the termina- tion two pairs of sebaceous glands are noted, as in other Marsupials. Fig. 20 (A) Rectal, and (B) Genito-Urinary (Vulval) Termination in Female Tasmanian Devil (Dasyurus Sarcophilus).
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