THE IXADEQUACY OF THE CELL-THEORY. II5 



"determinants"; the "determinant" as a colony of " bio- 

 phores," and the " biophore " as a colony of molecules. 



In proportion as division of labor is carried out, i)itcr- 

 dependcnce is increased, and the units become more and more 

 intimately associated. The struggle for existence is supposed 

 to extend to the cells, and even to the biophores. Symbiotic 

 relations are fought out, refined, and confirmed by natural 

 selection, and eventually reduced to a system of mutual adap- 

 tations which are fancied to be the basis of organic unity. 



Whether organization is wholly a matter of acquisition, and 

 whether it became possible only as a result of symbiotic ad- 

 vantages accidentally discovered in the struggle for existence, 

 need not here be discussed. It is enough for present purposes 

 to know that organization exists, and that organic unity 

 depends on intrinsic properties no less than does molecular 

 unity. 



It is not division of labor and mutual dependence that 

 control the union of the blastomeres. It is neither functional 

 econoviy nor social instinct that binds the two halves of an &g^ 

 together, but the constitutional bond of individual organiza- 

 tion. It is not simple adhesion of independent cells, but 

 integral structural cohesion. 



That organization precedes cell-formation and regulates it, 

 rather than the reverse, is a conclusion that forces itself upon 

 us from many sides. In the infusoria we see most complex 

 organizations worked out within the limits of a single cell. 

 We often see the formative forces at work and structural 

 features established before fission is accomplished. Cell- 

 division is here plainly the result, not the cause, of structural 

 duplication. The multicellular Microstoma behaves essentially 

 in the same way as the unicellular Stentor, or the multinucleate 

 Opalinopsis of Sepia. The Microstoma organization duplicates 

 itself, and fission follows. The chain of buds thus formed 

 bears a most striking resemblance to that of Opalinopsis, and 

 the resemblance must lie deeper in the organization than cell- 

 boundaries. 



Compare the results obtained by artificial division in two 

 such forms as Stentor and Hydra. The two courses of regen- 



