Organic Inheritance 19 



heritance, the two parents contribute between 

 them on an average one-half of each inherited 

 quality, one-fourth being contributed by each 

 of them. The four grandparents contribute 

 one-si:xteenth, or altogether one-fourth of the 

 inherited faculties, and the farther back one 

 goes the less Avill naturally be the influence. 

 Pearson, another authority, believes that par- 

 ents have relatively more influence than grand- 

 parents, as indicated in the above ratio, al- 

 though accepting the general principle of the 

 law of ancestral inheritance. 



It must be acknowledged that in respect to 

 organic heredity there are many gaps in our 

 knowledge, and it must also be borne in mind 

 that most of the studies of biologists have been 

 made upon plants and the lower animals and 

 their generalizations can only partly apply to 

 human beings. In the scheme of evolution, the 

 higher the animal the slower and more import- 

 ant becomes its period of growth. This is es- 

 pecially emphasized, as already noted, in hu- 

 man beings by the prolongation of the period of 

 infancy and the many subsequent years of 



