WHAT IS PHYSICAL LIFE 



have been experimentally proved to be 

 profoundly affected by purely chemical 

 agents, they appear to accept this as evi- 

 dence that it is all of a piece throughout, 

 and that further investigation will show 

 that one after another of supposed vital 

 phenomena will take their place in the list 

 of physico-chemical effects until no such 

 thing as vitality will remain. 



Thus one of the hitherto most myste- 

 rious of living processes, that of the cleav- 

 age and arrangement of cells in the early 

 stages of animal development, has been 

 shown to be fundamentally modified by 

 varying the chemical composition of the 

 fluids in which the animal living cells are 

 bathed. Professor Loeb, for example, 

 more than confirmed similar experiments 

 by other biologists, by demonstrating that 

 unfertilized eggs of echinoderms, or sea 

 urchins, when dipped in a dilute solution 

 of magnesium chloride, then went on to 

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