. The anatomy of the central nervous system of man and of vertebrates in general. Neuroanatomy; Central Nervous System. 58 ANATOMY OF THE CENTRAL NERVOUS SYSTEM. The Froriep fundaments, on the other hand, have an exclusively embryonic existence, and were, therefore, regarded by their discoverers as ontogenet- ically persistent rudiments of lost ancestral sense-organs; and were called hranchial cleft organs {Kiemenspaltenorgane). Definite traces of this embry- onic connection with the epidermis are manifest in the adult in the Acustico- facialis, the Glosso-pharyngeus, and Vagus; the Ivupffer s
. The anatomy of the central nervous system of man and of vertebrates in general. Neuroanatomy; Central Nervous System. 58 ANATOMY OF THE CENTRAL NERVOUS SYSTEM. The Froriep fundaments, on the other hand, have an exclusively embryonic existence, and were, therefore, regarded by their discoverers as ontogenet- ically persistent rudiments of lost ancestral sense-organs; and were called hranchial cleft organs {Kiemenspaltenorgane). Definite traces of this embry- onic connection with the epidermis are manifest in the adult in the Acustico- facialis, the Glosso-pharyngeus, and Vagus; the Ivupffer series corresponds to the Ggl. acusticum, Ggl. jugulare of the IX and the Ggl. jugulare of the X; from the Froriep series arise the Ggl. geniculatum (VII), Ggl. petrosum (IX), and the pneumogastric ganglion (X).. Fig. 26a.—Cross-section through the posterior part of the head of a shark embryo, of twelve millimeters' length. The section passes through the fourth visceral cleft (4) and through the vagus ganglion with its two epidermal con- tacts: the Kupffer fvmdament (Kupflfer Anl.) and the Froriep fundament, re- spectively,—the lateral and the epibranchial fundaments, (t, a, Arteries. V, Jugular vein. (After Froriep.) The olfactory nerve occupies an exceptional position. At one time its primitive ganglion seemed to be quite absent. The olfactory ganglion of His arises independent of the nasal pit—the Kupffer fundament—as a purely lateral ganglion, migrates away from the nasal pit, approaches the brain, and fuses completely with the olfactory bulb. The nasal pit behaves also in a special way, in so far as it is the only one of the persistent funda- ments which retains the character of the primitive sense-organs. Its cells remain in situ as peripheral nerve-cells which send their neuraxons into the olfactory bulb. In the case of other sense-organs—, the auditory pit—a separation takes place: the original peripheral nerve-cells migrate inward. Please note that these
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