The Cochlea of the Dolphin, Tursiops truncatus: General Morphology.

The anatomy of the cochlea of the dolphin Tursiops truncatus was studied in a number of specimens after fixation by vital perfusion, cellodin embedding, and serial sectioning. The results reveal the general structural relations and cellular detail up to the limits of light microscopy. A description is given of the variations of structure along the course of the cochlea, in which there are many departures from the typical mammalian form, especially in the compact quality of the tissues and the sturdiness of its elements. Apparently these features represent an adaptation of the cetacean ear to the reception of high-frequency sounds.