82 The Unity of the Organism 



Endorsement of E. B. Wilson's Proposal to Drop "De- 

 terminer" From the Vocabulary of Genetics 



In his Croonian Lecture having the title The Bearing of 

 Cytological Research on Heredity, E. B. Wilson said, "In 

 the meantime it would be well to drop the term 'determiner' 

 or 'determining factor' from the vocabulary of both cytol- 

 ogy and genetics." 5 If the facts and arguments set forth 

 in the preceding pages are valid, they constitute a demon- 

 stration that not only would it "be well to drop the term 

 'determiner,' " but that it must be dropped, at least in its 

 present application, before thought and investigation on the 

 mechanism of heredity can be free and in very deed truth- 

 seeking. "What we really mean to say," Wilson continues, 

 "is 'differential' or 'differential factor,' for it has become 

 entirely clear that every so-called unit character is pro- 

 duced by the cooperation of a multitude of determining 

 causes." So far as these statements go they are in strict 

 accord with the organismal standpoint maintained in this 

 volume, and we may also say, with the physical-chemistry 

 standpoint. 



Where attributes of adult organisms have been so defin- 

 itely correlated with particular chromosomes and possibly 

 parts of chromosomes of the germ-cells as seems to be the 

 case in the fruit flies, such chromosomes are unquestionably 

 differential, and since they stand at the very beginning of a 

 long and complex transforming and developing series, they 

 may very properly be called differential factors even though 

 they do not themselves participate substantively in the 

 transformation. The general similarity of their mode of 

 action to that of enzymes is certainly considerable : a minute 

 quantity of the substance is capable of inducing or facili- 

 tating the transformation of a large amount of other sub- 

 stance in a perfectly definite manner, and the inducing agent 

 is not itself consumed. 



