XII. 

 RUDIMENTARY ORGANS. 



The subject of rudimentary organs furnishes diffi- 

 culties against the theory of evolution. Have func- 

 tional organs become rudimentary? Have all rudi- 

 mentary organs been functional? Have organs not 

 only become rudimentary, but have they, in some in- 

 stances, disappeared entirely? 



Evolution must answer the first and third of these 

 questions in the affirmative, but to the second may 

 possibly give a qualified answer. 



As an example of rudimentary organs — all male 

 mammals except monotremes have rudimentary teats. 

 How did they acquire these organs? Were they orig- 

 inally functional in the males, and have they become 

 rudimentary by disuse? Shall we assume that the 

 males of the first mammals, which probably existed 

 in the Paleozoic, had functional mammse, and that 

 from these all living mammals have inherited them as 

 rudiments? 



The fact that all males possess them indicates that, 

 if they were ever functional, they became rudiment- 

 ary in the original mammalian stock, for this is more 

 reasonable than to assume that they separately became 

 rudimentary after the mammals had become differen- 

 tiated into groups. Whether we assume that they 

 were rudimentary from the first and that they never 

 were functional, or that, being at first functional, 

 they afterwards became rudimentary, it is evident 

 that as the merest rudiments they have survived 



through an immense period of time. 



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