Inaugural dissertation on the physiological inferences to be deduced from the structure of the nervous system in the invertebrated classes of animals : submitted to the Medical Faculty of the University of Edinburgh ... / by William B. Carpenter.

  • William Benjamin Carpenter
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Inaugural dissertation on the physiological inferences to be deduced from the structure of the nervous system in the invertebrated classes of animals : submitted to the Medical Faculty of the University of Edinburgh ... / by William B. Carpenter. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    .; i Conchifera it is more of an orange colour; and in the Gas- teropoda it is of a reddish Drown. It cannot be doubted that this corresponds with the grey or cortical substance of the nervous centres in Vertebrata. The manner in which it is disposed in reference to the nervous fibres, at once distin- guishes the ganglia of the Mollusca from those of the sym- pathetic nerve, or of the posterior roots of the spinal nerves, in Vertebrata. In the latter we observe the fibres continu- ous through the ganglia, and the grey matter interposed among them. In the former, the grey matter is confined to the centre, and is traversed by no fibres ; and the roots of the nerves which terminate in the ganglion are observed to penetrate to it, and then to diverge,—becoming, as it were, lost in its substance.* This is alike the case with what are believed to be, from their connections, both sensory and motor nerves. This structure obviously, therefore, re- sembles that of the centres of the cerebro-spinal system in Vertebrata; the connection of the roots of the nerves with the grey matter of the spinal cord, as well as that of the fibrous with the cortical portion of the brain, being exactly the same as that just described. These ganglia, then, may be regarded as holding precisely the same relation to the nerves which issue from them, as do the corresponding parts of the centres in Vertebrata. What these corresponding parts are will be the next subject of enquiry. 46. The cephalic ganglia must be regarded as analogous —not to any single portion of the Encephalon in Vertebrata —but in some degree to the whole. We find nerves of special sensation proceeding from them, certainly to eyes, per- haps also to olfactive organs ; as well as others of common sensation, supplying the tentacula and mouth. Hence we
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