INTRODUCTION 



phenomena, and that with their help we should succeed in con- 

 trolling such phenomena to a much greater extent than by any 

 other means. Organic chemistry has thrown but little light 

 upon the dynamics of living matter : and this may be partly due 

 to the fact that insufficient attention has been paid to the 

 electrolytes. It appeared to me that nothing would more 

 clearly demonstrate the sovereign role that electrolytes play in 

 the phenomena of life than by causing, if possible, with their 

 help, unfertilized eggs to develop into larvae. The ions by 

 whose aid I confidently expected to achieve success were the 

 hydroxylions. I had found that the development of fertilized 

 sea-urchin eggs depended upon the reaction of the solution, 

 and that a faintly alkaline solution was more favorable than a 

 slightly acid solution. This I attributed to an influence upon 

 oxidations in the eggs. For I had previously discovered that 

 without oxygen the fertilized sea-urchin egg can neither segment 

 nor develop. 



My first experiments toward causing unfertilized eggs to 

 develop by means of alkali consisted in exposing the eggs to sea- 

 water to which some sodium hydrate had been added, so as to 

 increase the alkalinity. These experiments were only partially 

 successful. In such sea-water, the eggs divided only once or 

 twice without developing into larvae. On the other hand, in 

 1899 I succeeded in inducing unfertilized sea-urchin eggs to 

 develop into larvae by exposing them for two hours to hyper- 

 tonic sea-water, i.e., sea-water to which had been added 

 sufficient salt or sugar to raise its concentration about 60 per 

 cent. Even pure (hypertonic) cane-sugar solutions were found 

 to induce development, but the larvae obtained in this case 

 were unable to develop to the pluteus stage. Six years later I 

 found that, within certain limits, the developmental effect of 

 the hypertonic solution increases with the concentration of the 

 hydroxy lions. Moreover the hypertonic solution is only able 

 to produce its developmental effect if it contains free oxygen 



