Tuberculum impar

During the third week of embryogenesis there appears, immediately behind the ventral ends of the two halves of the first pharyngeal arch, a rounded swelling named the tuberculum impar or median tongue bud, which was described by His as undergoing enlargement to form the buccal part of the tongue.

More recent researches, however, show that this part of the tongue is mainly, if not entirely, developed from a pair of lateral swellings which rise from the inner surface of the pharyngeal arch and meet in the middle line. The site of their meeting remains post-embryonically as the median sulcus of the tongue.

The tuberculum impar disappear in an adult tongue