It shifts in position with the position of the gill-slit, but there can be no backwards extension of the cavity.
He describes how in the embryo of the Blenny there is a short, thick arch between the first gill-slit and the mouth.
He refused to accept Huschke's derivation of the auditory meatus from the first gill-slit.
Between these two arches he found an opening, just as between two gill-arches a gill-slit.
gill slit n.
One of several rudimentary invaginations in the embryonic surface, present during development of air-breathing vertebrates and corresponding to the functional gill slits of aquatic species.
|gill slit |
In primitive chordates and cartilaginous fish, such as sharks, one of several narrow external openings connecting with the pharynx through which water passes to the exterior, thereby bathing the gills. Bony fish and all other vertebrates, including humans, have rudimentary gill slits during their embryonic stage.