30 



Similarity between the distribution of species and 

 varieties. Cya7iura stclleri. 



" Present distribution cannot be accounted for by 

 difference in physical conditions. 



Importance of barriers (Darwin, pp. 322-329). 



Affinity of productions of the same continent. 



" Centres of Creation." 



Some facts accounted for by the past history of 

 the earth (See Wallace, pp. 338-355). 



Facts to be explained. 

 Conditions of distribution. 

 Permanence of oceans. 

 Oceanic and continental areas. 

 Madagascar and New Zealand. 

 The thousand fathom line. 

 The distribution of Marsupials. 

 The distribution of Tapirs. 

 Powers of dispersal. 



3. The evidence from Palaeontology. 



(Romanes, 1892, pp. 156-203.) 



Incompleteness of the record. 



Difficulty of preservation. 



Full history of specific changes not to be ex- 

 pected. 



Palaeontology furnishes no proof against evolu- 

 tion. 



Le Conte's diagram of the succession of animals. 



Missing links. 



The development of horns. 



The tails of fishes. 



The tails of birds. 



Arclueoptcrix. 



