APPENDIX. 73 



adduced in the text— the Zielstrebigkeit (to use K. E. 

 Yon Bar's phraseology) displayed in the visible 

 paleontological development, the directness of advance 

 of the modifications to a final "goal." "The direct, 

 unswerving way in which development proceeds, how- 

 ever slowly, is not suggestive of many trials and fail- 

 ures in all directions save one." And again, "The 

 march of transformation is the resultant of forces 

 both internal and external which operate in a deftnite 

 manner upon a changeable organism and similarly af- 

 fect large numbers of individuals." 



The two points which I have here italicised are 

 actually the facts which separate phylogenetic from 

 common individual variation: the definite manner of 

 the change, repeated again and again without modi- 

 fication, and its occurrence in a large number of indi- 

 viduals. 



Still the two are not solely a result of observation, 

 deduced from paleontological data; they are also 

 a consequence of the theory of selection, as was shown 

 in the text. If the theory in its previous form was un- 

 able to fulfil this requirement, it is certainly now able 

 to do so after germinal selection has been added, and 

 it is not in any sense necessary to assume a difference of 

 character between phylogenetic and ontogenetic varia- 

 tions. Bateson and Scott are wrong in imagining that 

 I ask them "to abrogate reason" in pronouncing the 

 "omnipotence of natural selection." On the contrary, 

 the theory seems to me to accord so perfectly with the 

 facts that we might, by reversing the process, actually 

 construct the facts from the theory. What other than 

 the actual conditions could be expected, if it is a fact 

 that selection favors only the useful variations and 

 singles them out from the rest by producing them in 



