. The biology of marine animals. Marine animals; Physiology, Comparative. 524 THE BIOLOGY OF MARINE ANIMALS The nervous supply of the chromatophores is derived from the sympa- thetic system. There are chromatic centres in the and from these centres nerve tracts run through the cord. The efferent fibres have the usual arrangement characteristic of the sympathetic system, and arise from pre- ganglionic neurones in the lateral cord. They enter the vertebral ganglia via white rami communicantes, and form synapses there with post-ganglionic neurones (Fig. ). The fibres continue their cour
. The biology of marine animals. Marine animals; Physiology, Comparative. 524 THE BIOLOGY OF MARINE ANIMALS The nervous supply of the chromatophores is derived from the sympa- thetic system. There are chromatic centres in the and from these centres nerve tracts run through the cord. The efferent fibres have the usual arrangement characteristic of the sympathetic system, and arise from pre- ganglionic neurones in the lateral cord. They enter the vertebral ganglia via white rami communicantes, and form synapses there with post-ganglionic neurones (Fig. ). The fibres continue their course through sympathetic trunks, and finally enter grey rami to reach the spinal nerves, in which they. Fig. The Effects of Interrupting Peripheral and Sympathetic Nerves on Coloration of the Turbot Scophthalmus {Rhombus) maximus (a) Darkening of an area of the skin as the result of cutting spinal nerve branches; (b) darkening of an area of the body and chin, as the result of cutting spinal nerve branches and the inferior maxillary branch of the trigeminus; (c) darkening of the posterior region as the result of destruction of the sympathetic chain in the posterior haemal canal. (From Pouchet, 1876.) extend to their terminations about the chromatophores in the skin. It has been found that the pre-ganglionic chromatic fibres emerge from the cord at a restricted level, in Crenilabruspavo, for example, at the eighth vertebra. On reaching the sympathetic chain they take ascending and descending paths, and form synapses with many post-ganglionic neurones along their course. Descending fibres enter the tail and ascending fibres finally enter the head, whence they reach the periphery through cranial nerves. The mechanism of nervous control of chromatophores in teleosts has been investigated by nerve section, stimulation and the effect of "autono-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - color
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