No. 5S0] ORIGIX OF S1XGLK (11. [It. I ( 77.7,' > 



characters we know nothing, we stand by the theoretic 

 opinion that: Selection is operating always upon the sum 

 of all the movements, actions and reactions of characters 

 known as the Organism and upon all single characters 

 of survival or elimination value. 



Very recent is Bateson's enunciation 24 of the novel 

 hypothesis that we may have to forego the theory of 

 addition of germinal factors or determiners and substitute 

 a theory of variation by loss of "factors": 



Paleontology affords only indirect evidence as to ger- 

 minal "factors" but it offers the most positive testimony 

 both as to evolution largely by the loss of characters, as in 

 the case of the family of horses, and evolution largely by 

 the addition of characters, as in the family of titanotheres 

 displayed in Fig. 10. It is the constant addition of new 

 somatic characters in the evolution of members of the 

 latter family which forms the background of the present 

 address. Whether the incessant and most impressive ad- 

 dition of the new somatic characters which transform Eoti- 

 tanops into Brontotherium are the visible result of a sub- 

 traction of germinal "factors" may be a subject for 

 metaphysical discussion, but is certainly without the 

 bounds of all natural evidence. A natural view is that the 

 invisible germ is being continuously enriched with the vis- 

 ible body by processes of which we can form no concep- 

 tion whatever. 



2 *Bateson, Wm, "Heredity." Inaugural Address of President to The 



