Median fibrous septum

Lingual septum
The mouth cavity. The cheeks have been slit transversely and the tongue pulled forward. (Lingual septum is visible at center of tongue, but not labeled.)
A pierced tongue, which has not accommodated for swelling
Details
Latin	septum linguae
Anatomical terminology []

The lingual septum consists of a vertical layer of fibrous tissue, extending throughout the entire length of the median plane of the tongue, though not quite reaching the dorsum.

It is thicker behind than in front, and occasionally contains a small fibrocartilage, about 6 mm. in length.

It is well displayed by making a vertical groove along the tongue called the median sulcus.

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)