MYSTERIES OF LIFE AND MIND 



Eight or nine years before, Dr. Loeb had ob- 

 served that if the fertilized eggs were placed in sea- 

 water made a little more concentrated by adding 

 some neutral salt, they do not begin to divide and 

 grow as they do ordinarily. The process of cell- 

 division seems inhibited. But if afterwards they 

 were put back into normal sea -water, they at 

 once broke up into a large number of cells, instead 

 of dividing successively into two, four, eight, six- 

 teen, thirty-two cells, etc., as they usually do. Sev- 

 eral stages, so to speak, have been skipped over. 

 In other words, the process of development of the 

 animal had gone on, in a measure, without the 

 fact being apparent. 



While continuing his studies on the effects of 

 salts upon life phenomena, he was led to the fact 

 that the peculiar actions of the protoplasm are in- 

 fluenced to a great extent by the ions contained in 

 the solutions which surround the cells. By chang- 

 ing the relative proportions of the ions, it is possible 

 to vary the physiological properties of the proto- 

 plasm, and thus to impart to a tissue properties 

 which it does not ordinarily possess. Pursuing 

 this idea, he took unfertilized eggs, and after many 

 trials succeeded in finding a solution of chloride of 

 magnesium which caused the eggs to develop to the 

 same stage that they do normally in an aquarium. 

 Subsequently it was found that other salts and the 



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