. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. 148 COMPARATIVE ANATOMY and the constrictor of the gill-arches, the nerves arise from the " electric lobe" of the medulla oblongata, a single branch coming also from the trigeminal nerve; in all psendo- clectric Fishes, as well as in Gymnotus, in which over two hundred nerves pass to the electric organ, they arise from the spinal cord, and are probably in close relation with the ventral cornua of the latter, which nre particularly well developed in the last-named Fish. It is remarkable that the electric nerve
. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. 148 COMPARATIVE ANATOMY and the constrictor of the gill-arches, the nerves arise from the " electric lobe" of the medulla oblongata, a single branch coming also from the trigeminal nerve; in all psendo- clectric Fishes, as well as in Gymnotus, in which over two hundred nerves pass to the electric organ, they arise from the spinal cord, and are probably in close relation with the ventral cornua of the latter, which nre particularly well developed in the last-named Fish. It is remarkable that the electric nerves of Malopterurus arise on each side from a single enormous lens-shaped nerve-cell, which, lying in the neighbourhood of the second spinal nerve, is continued into a very large primitive-fibre which passes towards the end of the tail, dividing as it goes. This fibre is invested by a thick Fig. 120.—Elec- TKic Prisms of Torpedo mar- morata. (Semi- diagrammatic. ) Experiments have shown that all Electric Fishes are proof against the electric cuirent, with the limitation that muscles and nerves—even the electric nerves themselves— separated out from the body are capable of being excited by the current. '' The last and most important question with regard to the Electric Fishes is naturally concerning the mechanism whereby the electric plates become temporarily charged with electricity. The reply to this ques- tion, although probably not so difficult a one as that relating to the mechanism of muscular contraction, is still far from being answered " (Du Bois-Reymond). The only thing that can be stated with certainty is, that the electromotive force is under the influence of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wiedersheim, Robert, 1848-1923; Parker, William Newton, 1857-19
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