INTRODUCTION 



some. Since, according to the gene-theory, it represents 

 in the body of the organism in which it exists a character 

 which another gene (or genes) in another chromosome 

 (or other chromosomes) may represent, it appears to act 

 not singly but as part of the chromosome-structure and of 

 the whole chromosome-garniture. We know that life 

 exists in size below that recognizable by the microscope; but 

 we possess no proof that life consists of a single gene. Much 

 has been said recently of the size of the gene; but we should 

 recall that size does not condition molecularity. Molecules 

 vary in size. In addition, many investigators have become 

 cautious in speaking of the gene as a molecule, preferring 

 the idea that it may be several molecules. 



The most potent objection to the gene-molecule- (or 

 molecules) concept as the unit of life lies in the fact that the 

 gene-theory fails to explain how a single cell, the egg, 

 becomes a complex animal. A detailed discussion of 

 this point is given beyond. Here it suffices to say that 

 a particle (or all the particles together) which is only 

 in part engaged in the unfolding of life during its course 

 from Qgg to adult can not constitute life itself.^ The 

 conception of a hypothetical life-molecule is barren and 

 indicates again the limitation of the quantitative method 

 of analyzing life below the level where life is. The investi- 

 gator of the living state can and must use physics and 

 chemistry since the living state is a zone in nature and 

 his method of investigation can parallel that of the physical 

 scientist inasmuch as he finally comes to the unit-organi- 

 zation of life. Below this he can not go, for life is the 

 harmonious organization of events, the resultant of a 

 communion of structures and reactions. 



In general, the organization of living matter, that is, of 

 protoplasm, appears as consisting of two components, a 

 nuclear and a cytoplasmic. Although most often these 



^ Bui cf. Jennings, ^93^' 



7 



