Chapter VII 



THE CELL-THEORY NOT SUFFICIENT FOR 

 EXPLAINING THE ORGANISM 



IN tin- preceding chapter the cell-theory was shown to 

 bo inadequate as a complete explanation of the organism 

 when tested by studies of embryonic development and by 

 experiments on isolated cells and tissues. We now proceed 



to consider other phase's of the theory which still further 

 show its limitations. 



More General Inadequacy of the (.'ell-Theory 

 (a) As Tested by the Regeneration and Restitution of 



I Mat II a ted O rya u is ni .v 



Few topics of research have a more instructive bearing 

 on the hypothetical portion of the cell-doctrine than has 

 that of regeneration, taking the word in its general meaning. 

 Attention may be called first to the far greater inclination 

 of investigators to neglect cells as such when studying the 

 re-development of organisms that have been deprived of 

 some of their parts than when dealing with their development 

 from the germ. 



Such problems as those of cleavage, of molecular be- 

 havior, and of cell-lineage, which stand out so conspicuously 

 in most resc;i relics on ordinary embryonic development, par- 

 ticularly those concerning themselves primarily with early 

 stages, are for the most part conspicuous by their absence 

 in studies on the rehabilitation of mutilated organisms. 



rndoubtedly one reason, perhaps the chief reason, for 



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