. The physiology of the Invertebrata. ABCFig. 62.—Nervous Systems of Polych^;ta. A = Polynbe squamata. B = SabelUi Jlahellata. C = Nereis a = cerebral ganglia. b = oesophageal = longitudinal commissures of ventral ganglia, Lumhricus are seen to contain a large number of nerve-cells along with the nerve-fibres. This is a characteristicfeature of Lumhricus and Peripatus. In Hirudo the nerve- PHYSIOLOGY OF THE INVERTEBRATA. 323 cells are confined to the ganglia; in this respect the nervesof the leech are like those of Astacus and the spinal cord ofthe Vertebrata. The nervous system
. The physiology of the Invertebrata. ABCFig. 62.—Nervous Systems of Polych^;ta. A = Polynbe squamata. B = SabelUi Jlahellata. C = Nereis a = cerebral ganglia. b = oesophageal = longitudinal commissures of ventral ganglia, Lumhricus are seen to contain a large number of nerve-cells along with the nerve-fibres. This is a characteristicfeature of Lumhricus and Peripatus. In Hirudo the nerve- PHYSIOLOGY OF THE INVERTEBRATA. 323 cells are confined to the ganglia; in this respect the nervesof the leech are like those of Astacus and the spinal cord ofthe Vertebrata. The nervous system of the Polychceta usually consists ofa chain of ganglia—one pair for each somite—connectedtogether by longitudinal and transverse commissures, whichdiverge between the cerebral ganglia and the succeedingpair, to allow of the passage of the oesophagus. The mostimportant differences presented by the nervous systems ofthe Polychceta result from the varying length of the transversecommissures. In Vermilia, Serpula, Sabella, these c
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinverte, bookyear1892
