Eimer's Organ - Discovery

Discovery

Theodor Eimer described the discrete microscopic organ of touch that densely populates the tip of the nose of the European mole Talpa europaea. The organ is named in his honour. In his original publication in 1871, he examined the structure of the nose, the distribution of the touch organs on the nasal skin, and the relationship of their density with the nose's use for palpation, to examine or explore by touching. Eimer established a connection between structure and function.

Eimer recognized the importance of the mole's nose to its behaviour. He stated in 1871: "The mole's snout must be the seat of an extraordinarily well developed sense of touch, because it replaces almost entirely the animal's sense of face, constituting its only guide on its paths underground." He estimated that the nose of the European mole was covered with more than 5,000 Eimer's organs, which were invested with 105,000 nerve fibres. He took the abundance of sensory innervation (stimulate a nerve or muscle) to affirm his contention that the nose's touch must represent the moles dominant facial sense. Eimer asserted that his interpretation was consistent with the common knowledge of his time. In his publication he noted that the extreme density of highly sensitive nerve fibres is the cause of a light blow to the snout being able to kill the mole instantly. Roughly 130 years after Eimer's discovery, Catania and colleagues recorded in 2004 striking behavioural evidence in favour of his conclusions, using a high-speed camera. Moles with the help of their Eimer's organs may be perfectly poised to detect seismic wave vibrations.