CHAPTER XL 



LATENT ELEMENTS. 



Latent Elements not very numerous. — Pure Breed. — Simplification of 

 Hereditary Inquiry. 



Latent Elements not very numerous. — It is not 

 possible that more than one half of the varieties 

 and number of each of the parental elements, latent 

 or personal, can on the average subsist in the off- 

 spring. For if every variety contributed its repre- 

 sentative, each child would on the average contain 

 actually or potentially twice the variety and twice the 

 number of the elements (whatever they may be) that 

 were possessed at the same stage of its life by either 

 of its parents, four times that of any one of its 

 grandparents, 1024 times as many as any one of 

 its ancestors in the 10th degree, and so on, which is 

 absurd. Therefore as regards any variety of the entire 

 inheritance, whether it be dormant or personal, the 

 chance of its dropping out must on the whole be equal 

 to that of its being retained, and only one half of the 

 varieties can on the average be passed on by inherit- 



