Summary 185 



justified of its children. So far as it goes, it fits all 

 the facts. 



5. The rock record shows that as age succeeded 

 age there was an advance in differentiation and inte- 

 gration, an emergence of finer and nobler forms of 

 life. From among Fishes there arose Amphibians, 

 from Amphibians came Reptiles, and these gave 

 origin to Birds and Mammals. The most ancient of 

 the extinct birds, Archaeopteryx, that lived in Juras- 

 sic times, had several reptilian features. There are 

 some archaic living animals, like the New Zealand 

 "Lizard," Sphenodon, which may be called "living 

 fossils," for they are the sole survivors of ancient 

 races, otherwise quite extinct. There are generalized 

 extinct types — e.g., among crocodilians — which link 

 together more specialized extant types. Some very 

 satisfactory palaeontological pedigrees have been 

 worked out, as in the case of horses. The pedigree of 

 modern elephants may be taken as a test case. 



6. Geographical evidences of evolution may be 

 illustrated by the occasional correspondence between 

 the extinct and the extant in the same area; by the 

 history of Marsupials; by the contrast between 

 Oceanic and Continental Islands as regards their 

 fauna and flora. The very interesting facts in regard 

 to the Galapagos Islands, notably as regards Giant 

 Tortoises and Giant Lizards, cannot be accounted 

 for except in terms of evolution. 



7. Anatomical evidence may be illustrated by 

 homologies — the same materials twisted and moulded 

 into a great variety of result ; by the transformation 



