60 UNIVERSAL EVOLUTION 



fossil specimens in the different geological formations 

 are generally those of extinct species. These have been 

 followed by others in seemingly quite regular succes- 

 sion, each adapted for a time to the slowly changing 

 environment, and especially to the climate, the feet to 

 the surface, the teeth and digestive organs to the 

 natural vegetation of the period, the morphology to 

 the local general features of sunshine, humidity, com- 

 position of the air, the electric and magnetic condi- 

 tions, and the necessity of any peculiar requirements, 

 in the method of obtaining their sustentation. These 

 general principles of variation and their causes run 

 through the whole fossil forms of flora and fauna. The 

 forms of one period differed in some particulars from 

 those of another, but only in modification, not in dis- 

 continuity, showing a close genetic affinity running 

 through the whole series, clearly indicating continuous 

 descent, and not discontinuous catastrophism. 



GEOGRAPHICAL DISTRIBUTION. Paleontology can only 

 give evidence of the evolution of species in geological 

 time. But geographical distribution furnishes argu- 

 ments from widespread location of species, in earth 

 space. If the theory of special creation were true, then 

 there is no reason why forms, whether fossil, or living, 

 adapted to a given environment, should not be found in 

 all localities, furnishing such environment. 



THE FAUNA OF AUSTRALIA. For example, the rab- 

 bit when carried in ships to Australia, found itself 

 so well adapted to the locality, that it overran the 

 island, until it was declared a nuisance. Other 

 mammals carried to the island throve as well. Yet the 

 only mammalian life indigenous to Australia. the 

 dingo being plainly an importation, is one of the 

 oldest and least developed kinds, the marsupial. The 



