PERIOD OF CUVIER.

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tive, and Intelligent animals, are an imitation of the fourbranches of Cuvier ; but, far from resting upon such adefinite idea as the divisions of Cuvier , which involve aspecial plan of structure, they are founded upon theassumption that the psychical faculties of animals presenta serial gradation, which, when applied as a principle ofclassification, is certainly not admissible. To say thatneither Infusoria, nor Polypi, nor Eadiata, nor Tunicata ,nor Worms feel, is certainly a very erroneous assertion.They manifest sensations quite as distinctly as many ofthe animals included in the second type, which are caEedSensitive. And as to the other assertion, that they moveonly by their excited irritability, we need only watch theStarfishes to be satisfied that their motions are deter-mined by internal impulses, and not by external excita-tion. Modern investigations have shown that most ofthem have a nervous system, and many even organs ofthe senses.

The Sensitive animals are distinguished from the thirdtype, the Intelligent animals, by the character of theirsensations. It is stated, in respect to the Sensitive ani-mals, that they obtain from their sensations only percep-tions of objects, a sort of simple ideas which they areunable to combine so as to derive from them complexones, while the Intelligent animals are said to obtainideas which they may preserve, and to perform withthem operations by which they arrive at new ideas. Theyare said to be Intelligent . Even now, fifty years afterLamarck made those assertions, I doubt whether it ispossible to distinguish in that way between the sensa-tions of the Fishes , for instance, and those of the Cepha-lopods. It is true, the structures of the animals calledSensitive and Intelligent by Lamarck differ greatly, but