MIRACLES OF SCIENCE 



It is obvious that the individual sea-urchin or frog 

 developed from an unfertilized egg must lack an en- 

 tire series of tendencies that come to the normal in- 

 dividual through the paternal strain. 



TWO LIVES FOR ONE 



The individual developed from an unfertilized egg 

 must thus be thought of as having a somewhat re- 

 stricted personality, owing to the fact that it has only 

 a single parent. But what shall we say of the con- 

 verse case in which an egg which would normally 

 develop into a single individual is bi-sected and made 

 to develop into two individuals? 



This no less interesting juggling with personalities 

 has been likewise shown to lie within the possibilities 

 of laboratory experiment. Dr. Hans Driesch, work- 

 ing at the Marine Biological Laboratory in Naples, 

 juggled with the eggs of even so relatively highly, 

 organized a being as the fish in this curious way. It 

 is well known that the original egg cell, which marks 

 the first stage of development of every living organ- 

 ism, high or low, begins its development after fer- 

 tilization by dividing into two cells. These two cells 

 divide presently into four; the four into eight, and 

 so on. 



In a word, the entire development of any organism 

 consists essentially merely of the formation of more 

 cells by division of pre-existing cells. The cells ulti- 

 mately become modified and differentiated into vari- 

 ous tissues, but their potentialities of development 

 are all pre-existent in the original egg cell. 



Dr. Driesch's experiment consisted in invading the 



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