Note 1087 — Chapter VII

The only formidable opposition made to Cuvier's arrangement has proceeded from the advocates of the doctrine of circular progression: a remarkable theory, of which Lamarck and Macleay are the real originators, and which is certainly supported by a considerable amount of evidence. Still, among the great majority of competent zoologists, the fourfold division holds its ground, although the constantly-increasing accuracy of microscopical observations has detected a nervous system much lower in the scale than was formerly suspected, and has thereby induced some anatomists to divide the radiata into acrita and nematoneura. Owen's Invertebrata, 1855, pp. 14, 15; and Rymer Jones's Animal Kingdom, 1855, p. 4. As, however, it seems probable that all animals have a distinct nervous system, this subdivision is only provisional; and it is very likely that when our microscopes are more improved, we shall have to return to Cuvier's arrangement. Some of Cuvier's successors have removed the apodous echinoderms from the radiata; but in this Mr. Rymer Jones (Animal Kingdom, p. 211) vindicates the Cuverian classification.