ON THE MORPHOLOGICAL VIEW OF NATURE. 237 



The problem of organisation was much easier in deal- 

 ing with plants than with animals. In the former there 

 seems to be only one organ or system of organs definitely 

 developed and marked off namely, the organs of fructi- 

 fication ; and these had accordingly served Linnaeus and 

 his successors as the leading character for their de- 

 scriptive classification. In animals there are, or seem to 

 be at least, four or five well-defined and separated sys- 

 tems of organs. The selection, for the purposes of 

 classification and morphology, was much more difficult. 

 Accordingly we find Cuvier, who between the years 

 1795 and 1817 devoted himself to the morphological 

 and anatomical study of the animal kingdom, hesitating 

 in the selection of the leading character according to 

 which he should classify and arrange it. As I have 

 had occasion to remark above, 1 he finally in 1812 

 settled on the nervous system as the leading character 

 governing the figure of an animal organism. 2 Before 



pose, but of no other value. The 

 others, known as ' natural ' classi- 

 fications, are arrangements of ob- 

 jects according to the sum of their 

 likenesses and unlikenesses, in re- 

 spect of certain characters ; in 

 morphology, therefore, such classi- 

 fications must have regard only to 

 matters of form, external and in- 

 ternal. And natural classification 

 is of perennial importance, because 

 the construction of it is the same 

 thing as the accurate generalisation 

 of the facts of form, or the estab- 

 lishment of the empirical laws of the 

 correlation of structure " (Huxley in 

 'Life of Owen,' vol. ii. p. 283). 



1 See vol. i. p. 130 of this history. 



2 On the gradual development of 

 Cuvier's classification see Carus, 

 ' Geschichte der Zoologie,' pp. 602, 



32. 



Cuvier. 



612, 614. "It did not escape 

 Cuvier that the idea of subordina- 

 tion is artificial, and that the im- 

 portance of an organ can only be 

 fixed by experience namely, 

 through the proof of its constancy. 

 Nevertheless he follows this prin- 

 ciple, but naturally becomes vacil- 

 lating. Thus in 1795 he names 

 the organs of reproduction, to the 

 action of which the animal owes its 

 existence, and the organs of cir- 

 culation, on which depends the 

 individual preservation of the 

 animal, as the most important, 

 whilst in 1812, following the 

 example of Virey, he declares the 

 nervous system to be that system 

 for the maintenance of which the 

 other systems solely exist" (loc. 

 cit., p. 602). 



