406 HEREDITY AND ENVIRONMENT 



can at all reasonably be represented as an un- 

 packing of an original complex which con- 

 tained within itself the whole range of diversity 

 which living things present." This is as ex- 

 treme preformation in the field of inheritance 

 factors as was the old theory of emboitement in 

 the field of developed characters; it is devolu- 

 tion rather than evolution since it assumes that 

 the earliest organisms were genetically the 

 most complex. 



But if, as is often said, evolution from the 

 amceba to man necessarily involves the addi- 

 tion of many new inheritance factors it does 

 not involve additions from without as Bateson 

 assumes. New hereditary factors are to be 

 thought of as we think of new chemical com- 

 pounds, which are formed by new combinations 

 of the same old elements, or as we think of new 

 elements, such as helium and radium emana- 

 tion, which are formed by dissociation of ra- 

 dium. As compared with chemical elements the 

 factors of heredity are probably very complex 

 things and the new factors which appear in the 

 course of evolution probably arise as new com- 

 binations of factors or parts of factors previ- 



