Permanence and Evolution. 113 



the principle of descent must be conceded as 

 the only one by which all future researches 

 into the structure of the extinct world must be 

 guided." 



Here we find, very well expressed, the (as it 

 appears to me) fundamentally erroneous mode 

 of thought of which I am speaking. When he 

 asks why, on the hypothesis of special creation, 

 the carpal and tarsal bones of the paridigitata 

 are all formed on one plan, it is as if any one 

 should ask, why do the other bodies of the uni- 

 verse, as judged by the spectrum and the analysis 

 of meteorites, contain the same elements, i.e., 

 the same combination of sensible properties as 

 this earth does, instead of exhibiting any groups 

 of attributes that the mind can picture ? Why 

 do all the planets turn on their axes ? Why 

 are the laws of light the same, whether it 

 proceeds from our sun, or from the remotest 

 fixed star which the telescope can reveal ? Why 

 do chemical elements combine in definite pro- 



I 



