" DTSTELEOLOGY. IO9 



ablest living representative of this science, could say witli 

 perfect justice, that the Theory of Descent opened a new 

 period in Comparative Anatomy, and that the former is 

 the touchstone of the latter. "So far, no experience in 

 Comparative Anatomy is contradictory to the theory of 

 Descent; all rather lead to it. So that the theory will 

 receive back from the science that which it has imparted 

 to its methods; namely, clearness and certainty." Formerly, 

 the remarkable internal similarity of structure in organisms 

 had been a source of wonder, incapable of explanation. 

 Now, however, we can understand the causes of these facts, 

 and can prove that this wonderful uniformity is simply the 

 necessary consequence of Heredity from common ancestral 

 forms, and that the striking dissimilarity of the external 

 form is the necessary consequence of Adaptation to the 

 outward conditions of existence. 



There is a special branch of Comparative Anatomy 

 which is peculiarly interesting in this respect, and at the 

 same time of the most extended philosophical significance. 

 This is the science of Rudimentary Organs, which we may 

 call, in reference to their philosophical consequences, the 

 Doctrine of Purposelessness, or Dysteleology. Almost 

 every organism, with the exception of the lowest and 

 most imperfect, and especially every highly developed vege- 

 table or animal body, man as well as others, possesses one or 

 more structures which are useless to its organism, valueless 

 for its life-purposes, worthless for its functions. Thus all of 

 us have in our bodies various muscles which we never use ; 

 for example, the muscles in the external ear and the parts 

 immediately surrounding it. These outer and inner ear 

 muscles are of great use to most Mammals, especially such 



