(…) The anatomy of the odontocete brains indicates that they can taste but cannot smell. Apparently, when the blowhole migrated to the top of the head, the neural pathways for smell were sacrificed’ (Caldwell & Caldwell, 1972). Today it is generally accepted that toothed whales are unable to smell because of the above mentioned observation.
However in the nose of three harbour porpoises a large number of chemoreceptor cells have been discovered during a histological investigation of the olfactory regions. Why are the olfactory regions and olfactory cells retained, if at the same time the olfactory nerves are sacrificed? What is the function of such cells? (…)