Note 281 — Chapter IX

The conclusion here arrived at with reference to the anterior roots, is opposed to the observations of both Gegenbaur on Hexanchus, Jenaische Zeitschrift, Vol. VI., and of Jackson and Clarke on Echinorhinus, Journal of Anatomy and Physiology, Vol. X. These morphologists identify certain roots springing from the medulla below and behind the main roots of the vagus as true anterior roots of this nerve. The existence of these roots is not open to question, but without asserting that it is impossible for me to have failed to detect such roots had they been present in the embryo, I think I may maintain if these anterior roots are not present in the embryo, their identification as vagus roots must be abandoned; and they must be regarded as belonging to spinal nerves. This point is more fully spoken of at p. 428.