HEREDITY 503 



of continuous experimenting, that the germinal variations are tested 

 and sifted. 



The conception of the organism as a historic being is well il- 

 lustrated by the facts of heredity and development. There is the 

 inertia of the great mass of the inheritance, much of which is of 

 very ancient origin. There is a striking persistence of vestigial 

 structures and even habits. There is remarkable staying power in 

 unit characters. There is an indubitable recapitulation of phylogeny 

 in ontogeny, especially in organogenesis. The enregistering of 

 past gains is probably to be thought of in the light of the continuity 

 of the germ-plasm, for it seems that organic progress emerges 

 from within and is not impressed from without. 



The individual organism is the outcome of a hereditary nature 

 developing in an appropriate nurture. The direction of development 

 is mainly intrinsic, but the degree of expression attained bears 

 some relation to the extrinsic systematisation, what may be called 

 the external heritage. In Man's case in particular, where the nur- 

 ture is very subtle and very plastic, much may be made that is 

 not born. 



A study of the facts of heredity engenders a fatalistic impression : 

 the hand of the past has such a heavy grip. But " the other side 

 of heredity " must be considered, — the persistence of the stable, 

 the continual emergence of the new, the influence of nurture on 

 the individual, and the dominance of the social heritage. It is 

 important to bear in mind that each organism is in some degree 

 a new individuality with some measure of indeterminateness, and 

 made as well as born. 



The modern study of heredity forcibly suggests that the per- 

 sonality is a unique combination of many strands which go back 

 into antiquity. The strands are ancient but, as Jennings i)uts it, 

 each knot is new. It is tied afresh at the beginning of each new 

 life, and this implies some measure of uniqueness and freedom in 

 the self. Our characteristic strands do in some measure exist in 

 other combinations elsewhere, and may last on, unfortunately as 

 well as fortunately, when our particular knot is untied. 



