214 



Geological Evidence of Origin of Species. 



of America. A continent in the southern Pacific has sunk 

 out of sight, and left a few coral islands as monuments 

 of its extinction. To account for the Jurassic facies of the 

 Australian fauna and flora, we have only to assume the sepa- 

 ration of that continent from the rest of the world subsequent 

 to the Jurassic period ; and that, in other parts of the world, 

 new types were elaborated, which were unable to reach Aus- 

 tralia on account of its permanent isolation. Changes in the 

 distribution of land and sea would in like manner shift the 

 area of other zoological provinces. 



I have not pretended in this paper to give a complete ar- 

 gument. I have simply enumerated a few facts illustrating 

 two lines of geological evidence, both of which seem to point 

 towards evolution. These facts will suffice to explain the 

 toe? of evidence with which geology supplies us, though they 

 do not give the full strength of the argument. They com- 

 pose but one branch of a wide range of territory. Geology 

 knows nothing of living forms. Its witnesses are dead and 

 buried, though, happily, their sepulchres are with us to this 

 day. It is for the student of the living world to reveal the 

 startling facts of embryology ; to unfold the testimony of 

 rudimentary organs ; to expound the variations of species by 

 domestication and by external physical conditions ; to show 

 how the variations are perpetuated or destroyed ; to discuss 

 the laws of breeding between different varieties and species ; 

 and to explain the principles of geographical distribution. 

 My general conclusion is that evolution accounts for the facts 

 of natural history in general, and of palaeontology in partic- 

 ular, better than any other yet suggested. This may not 

 amount to demonstration, but it reaches high probability, 

 to a degree of probability which is marvellous when we con- 

 sider how little study has as yet been given to the subject. 

 At any rate, the number of eminent converts which have 

 been made to the hypothesis should raise it above the level 

 of unreasoning ridicule and disingenuous caricature. 



