Control of Heredity: Eugenics 283 



nomena of "multiple allelomorphism" (p. 98) prove that recessive 

 characters are not the result merely of, the absence of dominant 

 ones. On the other hand many things suggest that recessive 

 genes may originate from dominant ones by a process of de- 

 gradation. In many of the mutations studied by deVries, Bate- 

 son, Morgan and others some factor seems to have undergone 

 degradation and Bateson suggests that at present all new forms 

 arise only by the loss of factors or by the fractionation of factors 

 and that new factors are not added from without. This leads him 

 to inquire "whether the course of evolution can at all reasonably 

 be represented as an unpacking of an original complex which 

 contained within itself the whole range of diversity which living 

 things present." This is as extreme preformation in the field of 

 inheritance factors as was the old theory of "emboitement" in 

 the field of developed characters ; it is devolution rather than evo- 

 lution since it assumes that the earliest organisms were geneti- 

 cally the most complex. 



But if, as is often said, evolution from amoeba to man neces- 

 sarily involves the addition of many new inheritance factors it 

 does not involve additions from without as Bateson implies. New 

 hereditary factors are to be thought of as we think of new chemical 

 compounds, which are formed by new combinations of the same 

 old elements, or as we think of new elements, such as helium and 

 radium emanation, which are formed by dissociation of radium. 

 As compared with chemical elements the factors of heredity are 

 probably very complex things and *lr ^w factors which appear in 

 the course of evolution probably arise as new combinations of 

 factors or parts of factors previously present. Nowhere in the 

 entire process of organic evolution is there any evidence that 

 new factors are "extrinsic additions" or are created de novo. 

 The whole process is one of evolution, that is of new combina- 

 tions of existing units, having new qualities which are the re- 

 sults of these new combinations. 



If these changes in the germplasm may be induced by extrinsic 



