EXISTENCE AND DISTRIBUTION OF MARINE ORGANISMS. 409 



present, tending to a complete uniformity of climate over the earth's 

 surface. 1 When we take into consideration the effect of the earth's 

 atmosphere, a sun with a diameter even half that here indicated would 

 account for tho paleothermic phenomena made known by the records 

 of the past life on the globe. When seeking a rational explanation of 

 the gradual evolution of the surface features of the globe, it is neces- 

 sary to take into account the contemporaneous evolution of the other 

 members of the solar system, and especially that of the central luminary. 



1 Blandet. Bull. Soc. Geol. tie France, Tom. 25, p. 777, 181.8. 



