Note 135 — Chapter VI · WHAT IS TAUGHT BY EMBRYOLOGY?
Reading edition
Kleinenberg, Hydra; Eine Anatomisch-Entwickelungs-Untersuchung, 1872, p. 11. Eimer, Zoologische Studien auf Capri, 1873, p. 66.
A similar formation is described by Dr. Allman in the Myriothela; he says, however, that he has never been able to trace a direct continuity of the caudal processes of the cells with muscular fibrils. He believes that the processes make their way to the muscular layer through undifferentiated protoplasm.—Philos. Transactions, Vol. CLXV. Part II. p. 554.
An intermediate stage between this neuro-muscular tissue and the two differentiated tissues seems presented in the Nematoid worms which have muscles that send off processes into which the nerves pass. Gegenbaur declares his inability to decide whether these processes are muscles or nerves. Bütschli thinks the nerve-process blends with the muscle-process.—Archiv für mikros. Anatomie, 1873, p. 89.