410 ON THE ORIGIN OF SPECIES 



possessor, will be saved as far as is possible, will 

 probably often come into play ; and this will tend 

 to cause the entire obliteration of a rudimentary 

 organ. 



As the presence of rudimentary organs is thus 

 due to the tendency in every part of the organisation, 

 which has long existed, to be inherited — we can under- 

 stand, on the genealogical view of classification, how it is 

 that systematists have found rudimentary parts as useful 

 as, or even sometimes more useful than, parts of high 

 physiological importance. Rudimentary organs may be 

 compared with the letters in a word, still retained in 

 the spelling, but become useless in the pronunciation, 

 but which serve as a clue in seeking for its derivation. 

 On the view of descent with modification, we may con- 

 clude that the existence of organs in a rudimentary, 

 imperfect, and useless condition, or quite aborted, far 

 from presenting a strange difficulty, as they assuredly 

 do on the ordinary doctrine of creation, might even 

 have been anticipated, and can be accounted for by the 

 laws of inheritance. 



Summary. — In this chapter I have attempted to show, 

 that the subordination of group to group in all organisms 

 throughout all time ; that the nature of the relationship, 

 by which all living and extinct beings are united by 

 complex, radiating, and circuitous lines of affinities into 

 one grand system; the rules followed and the difficulties 

 encountered by naturalists in their classifications ; the 

 value set upon characters, if constant and prevalent, 

 whether of high vital importance, or of the most trifling 

 importance, or, as in rudimentary organs, of no import- 

 ance ; the wide opposition in value between analogical 

 or adaptive characters, and characters of true affinity ; 

 and other such rules ; — all naturally follow on the view 

 of the common parentage of those forms which are 

 considered by naturalists as allied, together with their 

 modification through natural selection, with its con- 

 tingencies of extinction and divergence of character. 

 In considering this view of classification, it should be 



