MORPHOGENESIS 



799 



cytoplasm for at least 32 days did not prevent division in C. d/ffluens. 

 Within 24 hours after each cut, the regenerative processes were complete 

 and division occurred. Hartmann's initial attempts to substitute regenera- 

 tion for division in Amoeba proteus met with little success. The animals 

 lived for not more than 15 days. Later, however, he was able to contest 



Figure 183. Diagram 

 showing delayed regenera- 

 tion in Paramecium cauda- 

 tinn. The nucleated poster- 

 ior part of a Paramecium 

 transected anterior to the 

 division plane may divide 

 several times before form 

 restoration occurs in all of 

 its descendants. (Modified 

 from Peebles, 1912.) 



Phelps's results by successfully culturing A. proteus through a long 

 series of regenerations (Hartmann, 1928). One such series (protocol 3) 

 was discontinued after a four-month period, during which 130 re- 

 generations replaced the normal division process. In an equivalent period 

 the control series produced approximately 65 generations. It is Hart- 

 mann's conviction that Amoeba can be maintained in a healthy undivided 

 state for infinite periods by repeated operations. 



The question of "artificial immortality" through regeneration was 



