ON TUR MORPHOLOGICAL VIP:VV OF NATTRE, 



259 



correspondence of parts or organs based not so much on 

 external likeness as on similarity of origin. Ly admit- 

 ting the latter conception, the idea of origin, the rigidity 

 ■of the purely structural classification was lost. Morpho- 

 logy became the science, not of fixed, but of flowing 

 forms and structures. It is remarkable that Owen, in 

 following up this line of reasoning, was pre-eminently at- 

 tracted to the oracular writings of Oken, whose influence 

 his great forerunner Cuvier had combated with all his 



pended to tlie first volume of his 

 ' Hunteriaii Lecture.s,' as follows : 

 " ' Analogue ' — A part or organ in 

 one animal which has the same 

 function as another part or organ 

 in a different animal." " ' Hom- 

 ologue' — The same organ in dif- 

 ■erent animals under every variety 

 of form and function." He then 

 goes on to distinguish " special," 

 ^' general," and " serial " homology. 

 For a history of thought the imjwr- 

 tant point in all these discussions 

 is that, besides the similarity of 

 sti'ucture and the sameness of 

 function, relations and jjoints of 

 comparison of a different kind 

 were introduc:ed ; tliat these were, 

 with more or less clearness, traced 

 to development ; and that through 

 this the genetic view, the doctrine 

 of descent, was prepared by those 

 who, like Owen, were least ready 

 to accept it when it ap])eared in a I 

 ■definite form. In the light of this j 

 new view, of which the ne.\t 

 chapter will treat, the whole vocab- 

 ulary of the older morphologists I 

 required recasting. These older 

 views, which traced homology t<i 

 the existence of definite types, 

 models, or i)atterns possessing a 

 purely ideal existence, have been 

 termed Platonic, inasmuch as in 

 the philosophy of Plato the exist- 

 •C'uce of a world of ideal forms or 



archetypes served to explain what- 

 ever of order is found in the real 

 world of separate things. " The 

 term 'homology,'" says Prof. Itay 

 Lankester, " belongs to the Platonic 

 school, but is nevertheless used 

 without hesitation by those who 

 reject the views of that school. 

 Prof. Owen . . . would understand 

 by ' homologue ' the same firgan 

 in different animals under every 

 variety of form and function. . . . 

 But how can the sameness of an 

 organ under every variety of form 

 and function be established or in- 

 vestigated r This is, and always 

 has been, the stumbling-block in 

 the study of homologies without 

 tlie light of Evolutionism ; for, to 

 settle this question of sameness, 

 an ideal ' type ' of a group of 

 organisms under study had to be 

 evolved from the human mind, 

 after study of the comj)onent 

 members of the group ; and then 

 it could be assei-ted that organs 

 might be said to be the ' same ' 

 in two animals which had a 

 common representation in the 

 ideal type" {'Annals and Mag. 

 of Natural History,' 4th series, 

 vol. vi., 1870. p. 34, &c.) See also 

 Huxley in ' Life of Owen,' vol. ii. 

 p. 303, &c. ; and J. Arthur Thom- 

 son, 'The Science of Life,' p. 32 

 (1899). 



