HEREDITY 97 



inheritance as all that the organism is or has to start with 

 in virtue of this hereditary relation. Development is the 

 expression or realisation of the heritable qualities which 

 have their physical basis in the germ-cells, and it pre- 

 supposes an appropriate environment of nutrition and 

 " hberating stimuli " — " nurture " in the widest sense. 

 What the organism becomes is the resultant of two com- 

 ponents, inherited " nature " and external " nurture." 



