238 SCIENTIFIC THOUGHT. 



that, he had already adopted from Lamarck, 1 whose 

 many-sided genius has made a lasting impress on the 

 history of natural science in quite a different direction, 

 the broad morphological division of the animal kingdom 

 into animals with or without backbone, uniting under 

 the former designation the four first classes of Linnreus. 

 The more we follow Cuvier in the development of his 

 classifying attempts, the more we find the form, the 

 figure, the external and internal structure, urged as the 

 aspect from which the organisation of living creatures is 

 to be considered. To him fixity of form is the ever- 

 recurring character of organised beings as distinguished 

 from inorganic structures which depend on fixity of 

 matter. 2 The clearer enunciation of this fixity of form 

 is accompanied in Cuvier's view by the rejection of an 

 idea which, before him, had very largely governed the 

 speculations of naturalists. This idea, by which Charles 

 Bonnet has been immortalised in natural history, is the 

 conception of a graduated scale according to which living 

 creatures can be arranged viz., the celebrated ^chelle des 

 litres, coupled with the axiom, " Natura non facit saltus." 

 This idea Cuvier rejects as untenable, and introduces in 

 the place of it the conception of distinct plans called 

 Types." later "types," 3 according to which living beings are 



1 " An indirect inducement for a 

 more pointed enunciation of the 

 types of the various classes was 

 given by Lamarck in 1797 when 

 he placed the animals with white 

 blood as ' invertebrates ' in opposi- 

 tion to those with vertebrae which 

 expressions (a vertebres and sans 

 vertebres) come from him" (ibid., 

 p. 612). 



2 See Cuvier's ' Eloge of Hauy ' 



(El. iii. p. 156, &c.) and the extracts 

 from it and from the ' Regne 

 animal,' given in the first volume 

 of this History, p. 129 and notes 

 passim. 



3 According to Carus ( ' Gesch. d. 

 Zool.,' p. 615), the term "type," 

 which became current later, was 

 introduced.by De Blainville, a philo- 

 sophical naturalist who held a 

 kind of middle position between 



