[203] “Embryologische Mittheilungen.” Festschrift d. Naturfor. Gesell., Halle, 1879.
[204] In Man (Kölliker) the trabeculæ form from the first a continuous plate in front of the pituitary space, and the latter very early acquires a cartilaginous floor.
[205] The strongest evidence in favour of Huxley’s and Parker’s view of the nature of the columella is the fusion in the adult Sphenodon of the upper end of the hyoid with the columella (vide Huxley, No. [445]). From an examination of a specimen in the Cambridge museum I do not feel satisfied that the fusion is not secondary, but have not been able to examine the junction of the hyoid and columella in section. For a different view to that of Huxley vide Peters, “Ueb. d. Gehörknochelchen u. ihr Verhältniss zu. Zungenbeinbogen b. Sphenodon.” Berlin Monatsberichte, 1874.
[206] For some interesting remarks on the arrangement of these bones in Fishes, vide Bridge, “On the Osteology of Polyodon folium.” Phil. Trans., 1878.
[207] It is not impossible that the solution of the difficulty about the præopercular is to be found by supposing that the præopercular as it exists in Teleostei is derived from a dorsal dermal plate, and that in the Dipnoi this plate retains more nearly than in Teleostei its primitive position.
[208] The notochord appears also to enter into the posterior part of the region which ossifies as the basisphenoid.
[209] According to Kölliker there are two centres in Man in both the basisphenoid and presphenoid.