SCIENCE AND REVOLUTION 



At this stage, the ether-universe is filled with 

 spheres in various stages of development. Nat- 

 ural selection continues its work in them as it 

 does in the surface and the interior of the earth. 

 Vast oceans and marshes cover the surface of the 

 terrestrial globe at this stage, and in the depths 

 of the water myriads of plant and animal organ- 

 isms from the lowest types to advanced worms 

 are disporting themselves. These organisms are 

 all of them endowed with the essential faculties 

 of consciousness and will. But this conscious- 

 ness is as yet little above that of the primitive 

 inorganic life out of which it evolved. These 

 forms have no brain, although some of them 

 have developed the rudiments of a nerve system. 



Long before the Silurian period, we find in 

 those oceans certain worms which have devel- 

 oped a chorda, the first piece of cartilage indi- 

 cating the beginning of a thing which will in 

 course of time become the backbone of verte- 

 brate animals. Other worms continue without a 

 chorda and give rise to a separate line of inverte- 

 brate evolution. 



The earth and its oceans change. In the tran- 

 sition from the pre-Silurian to the Silurian period, 

 we meet with the ancestors of the modern Am- 

 phioxus, a little headless fish that has improved 



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