THE ARGUMENTS FROM MORPHOLOGY. 387 



in otlier members of the same group, sucL. organs are unre- 

 presented. Tliere remains only the doctrine of evolution ; 

 and to this, these rudimentary organs offer no difficulties. 

 On the contrary, they are among its most striking evi- 

 dences. 



§136. The general truths of morphology thus coincide in 

 tlieir implications. Unity of type, maintained under extreme 

 dissimilarities of form and mode of life, is explicable as re- 

 sulting from descent with modification ; but is otherwise 

 inexplicable. The likenesses disguised by unlikenesses, which 

 the comparative anatomist discovers between various organs 

 in the same organism, are worse than meaningless if it be 

 supposed that organisms were severally framed as we now 

 see them ; but they fit in quite harmoniously with the belief, 

 that each kind of organism is a product of accumulated 

 modifications upon modifications. And the presence in all 

 kinds of animals and plants, of fimctionally-useless parts 

 corresponding to parts that are functionally-useful in allied 

 animals and plants, while it is totally incongruous with the 

 belief in a construction of each organism by miraculous in- 

 terposition, is just what we are led to expect by the belief 

 that organisms have arisen by progression. 



