XII 

 THE HAZARDS OF THE PAST 



BERGSON, the new French philosopher, thinks 

 we all had a narrow escape, back in geologic 

 time, of having our eggs spoiled before they were 

 hatched, or, rather, rendered incapable of hatching 

 by too thick a shell. This was owing to the voracity 

 of the early organisms. As they became more and 

 more mobile, they began to take on thick armors 

 and breastplates and shells and calcareous skins to 

 protect themselves from one another. This tend- 

 ency resulted, he thinks, in the arrest of the en- 

 tire animal world in its evolution toward higher 

 and higher forms. These shells and armors begat 

 a kind of torpor and immobility which has con- 

 tinued down to our day with the echinoderms 

 and mollusks, but the arthropods and vertebrates 

 escaped it by some lucky stroke. Now you and 

 I are here without imprisoning shells on our 

 backs; but how or why did we escape.'^ Bergson does 

 not say. Was it a matter of luck or chance? Was 

 there ever a time when the stream of life tended to 

 harden and become fixed in its own forms like a 

 stream of cooling lava, or has the innate plasticity 



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