[292] Loc. cit.
[293] Vide Jackson and Clarke, loc. cit. The authors take a different view to that here advocated, and regard the ventral roots described by them as having originally belonged to the vagus.
[294] Vide Vetter, “Die Kiemen und Kiefermusculatur d. Fische.” Jenaische Zeitschrift, Vol. VII.
[295] A report of the lectures appeared in Nature.
[296] Vide Plate 8.
[297] The description of stage K and L, pp. [292] and [293], is a little inaccurate with reference to the number of the visceral clefts, though the number visible in the hardened embryos is correctly described.
[298] Vide on the development of the gills, Schenk, Sitz. d. k. Akad. Wien, Vol. LXXI, 1875.
[299] Vide Dohrn, Ursprung d. Wirbelthiere.
[300] Semper, in his most recent work, maintains, if I understand him rightly, that the head is in no sense a modified part of the trunk, but admits that it is segmented in a similar fashion to the trunk.
[301] Preliminary note upon the brain and skull of Amphioxus, Proc. of the Royal Society, Vol. XXII.