FACTS AND FINDINGS 33 



of a sea urchin destroyed, the remaining half developed 

 into an entire organism. Driesch finally showed that the 

 apparent difficulty lay in the physics of the various eggs 

 used for the experiment. In some cases the usual method 

 of egg division caused one portion to be heavier than 

 another and thus to sink into the surrounding nourish- 

 ment. When the heavier part was removed, the lighter 

 portion received but little or no nourishment, and, conse- 

 quently, could not develop. If, however, one used an egg 

 such as that of the sea urchin or even of the frog, and 

 placed it so that nourishment was forthcoming, then each 

 portion of the egg would result in a completely formed, 

 but often somewhat smaller, animal. 



Driesch finally came to the conclusion that to him, at 

 least, there was always something over and above what 

 the laboratory could find in the development of a complete 

 organism from such separate parts. He and his followers, 

 therefore, took the stand that satisfactory explanations 

 are more likely to come from an investigation of the 

 essence of life than from any purely embryological and 

 physiological experimentation in the laboratory. 



Here was a parting of the ways. Many sought to retrace 

 their steps and to start anew. Thus some became inter- 

 ested in behavior, and from behavior of the entire higher 

 organisms, or parts of those organisms, there was the in- 

 evitable tendency to go farther and farther back. If all 

 life was but the working out of actions and reactions of 



