Where did Life Begin? 31 



passed mainly toward the north pole in an 

 upper current, while the cooler and heavier 

 currents from the north have swept south- 

 ward hugging the surface of the continents, 

 laded with pollen, minute germs and spores, 

 and all the winged seeds of plants, bending 

 grass and shrubs and trees constantly to the 

 southward, and so, by small yearly increments 

 moving the whole vegetal kingdom through 

 valleys and along the sides of mountain ranges, 

 down the great continents, always moving 

 with, and never across these great surface 

 corrugations. It is unnecessary to add that 

 all insects and herbivorous animals would 

 follow the plants, or that the birds and car- 

 nivorous animals would follow the herbivor- 

 ous animals and the insects. So, too, the cur- 

 rents of the ocean have been established in 

 obedience to similar laws ; as hot water is 

 lighter than cold, great surface "currents have 

 been formed in both the Atlantic and Pacific 

 oceans, flowing from the equator to the arc- 

 tic regions, while the cooler and heavier cur- 

 rents from the Arctic have swept the floor of 

 both oceans from shore to shore to the south- 



