. Bulletin of the scientific laboratories of Denison University. Art. II.] Herrick, Gustatory Paths in Fishes. 57 Weigert sections show very clearly that fibers of the motor roots of the vagus and glossopharyngeus arise not only from the nucleus ambiguus but also from the motor layer of the vagal lobe, as has been well known since Mayser. My GoLGi preparations very rarely show good impregna- tions either of the cells of the motor layer or of the nucleus ambiguus. The latter have the form and arrangement which have been often figured, the main dendrites spreading out in the substantia reticular
. Bulletin of the scientific laboratories of Denison University. Art. II.] Herrick, Gustatory Paths in Fishes. 57 Weigert sections show very clearly that fibers of the motor roots of the vagus and glossopharyngeus arise not only from the nucleus ambiguus but also from the motor layer of the vagal lobe, as has been well known since Mayser. My GoLGi preparations very rarely show good impregna- tions either of the cells of the motor layer or of the nucleus ambiguus. The latter have the form and arrangement which have been often figured, the main dendrites spreading out in the substantia reticularis and reaching the extreme ventro-lat- eral border of the oblongata. Other smaller dendrites spread out within the nucleus itself and the neurite usually springs from the base of the main dendrite. The dendrites of the cells of the motor layer in some cases spread out within this layer, where they come into relation with the radial fibers which enter it from the layer of secondary neurones. Others reach out into the layer of secondary tracts and mot X Fig. 14. Transverse section of the vagal lobe of the right side of a young carp, 5 cm. long. GoLGi method. X 5°- Illustrating two intrinsic secondary- neurones of the vagal lobe whose processes extend inward to reach the motor layer, , secondary gusta- tory tract; sp. T^, spinal V tract. into the substantia reticularis (Fig 10), in both of which places they reach collaterals from the secondary gustatory tracts. It appears that in no case do the peripheral motor neurones come into direct relation with the peripheral gustatory neu- rones, but at least one intermediary element is always inter- posed. These elements may be the intrinsic neurones of the vagal lobe, for short reflex arcs, or the chief secondary gusta- tory neurones for more complex reflex connections reaching beyond the vagal region of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for r
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