Beli, : Improving the Human Rack 



is an inherited characteristic, and there- 

 fore hable to be handed down to some 

 of the descendants by any member of 

 the family, even by those members who 

 do not exhibit the pccuharity in their 

 own persons. 



These considerations lead us to the 

 conclusion that persons of normal 

 height will increase their liability to 

 have tall offspring by marrying into 

 families containing a number of tall 

 persons. In such a family the tendency 

 to produce tall people is evidently 

 an inherited characteristic ; and the nor- 

 mal and undersized members of the 

 family, as well as the taller members, 

 will have a tendency to transmit the 

 characteristic to some of their descen- 

 dants. The tendency is in the blood, 

 and the whole family possesses it. 



INFLUENCE OF ANCESTRY. 



In this connection the influence 'of 

 ancestry is most marked : 



(1). Where Normals (whose ancestors 

 on the whole were normal people) marry 

 Desirables (whose ancestors were chiefly 

 normal), the normal partners will prove 

 prepotent over the desirable partners in 

 affecting the offspring. The bulk of the 

 offspring will be normal; and only a small 

 proportion (say 10%) desirable. 



(2). But where Normals (with norjmal 

 ancestry) marry Desirables (whose parents 

 were desirable) the proportion of desir- 

 able offspring will be increased (say 20% 

 desirable). The potency of the desirable 

 partner to have desirable children is prac- 

 tically doubled, because of inheritance 

 from both parents; and the prepotency of 

 the normal partner is correspondingly re- 

 duced. 



(3). Where Normals (with normal an- 

 cestors) marry Desirables (whose grand- 

 parents as well as parents were desirable) 

 the proportion of desirable offspring will 

 be still further increased (say to 45%); 

 and the prepotency of the normal partners 

 will be reduced almost to zero. 



(4). Where Normals (with normal an- 

 cestry) marry Desirables (whose ancestors 

 for several generations back were all desir- 

 able) it is the desirable partner who be- 



comes prepotent over the normal partner 

 in affecting the offspring. The vast ma- 

 jority (say 90%) will be desirable. 



The influence of the normal partner 

 will be less and less according to the 

 number of desirable ancestors possessed 

 by the desirable partner. With a suf- 

 ficient number of generations of desir- 

 able ancestors, the desirable partner 

 is what is known as "thoroughbred" 

 in respect to the inherited characteris- 

 tic. The normal partners, on the other 

 hand, are not usually thoroughbreds for 

 the normal condition ; for if we examine 

 their ancestors for the same number of 

 generations back, we shall find, as a 

 rule, that some of the ancestors were 

 not normal: Some few were desirable, 

 and some few even undesirable. 



THOROUGHBREDS PREPOTENT. 



We breeders are familiar with the 

 prepotency of the thoroughbred animal 

 over the normal animal; and we can 

 therefore confidently assert that the 

 human throughbred will be equally 

 prepotent over the normal human being 

 in affecting the offspring. 



In spite of the smallness of the desir- 

 able class, its influence in improving the 

 normal population wotild be consider- 

 able should it contain a number of 

 highly prepotent individuals : For their 

 marriages with normal people would 

 result in the production of offspring 

 almost exclusively of the desirable type 

 (say 90 per cent, desirable). We should 

 also remember that the brothers and 

 sisters of the prepotent individuals will 

 also have a strong tendency to produce 

 desirable offspring where they marry 

 normals with normal ancestry. 



The liability of normal persons to 

 have desirable offspring will be in- 

 creased by marriages with persons of 

 the desirable class; and diminished by 

 marriages with undesirables. 



In the latter case the proportion of 

 undesirable children will be increased 

 and if the undesirable partner is de- 

 scended from undesirable ancestors the 

 proportion of undesirable children will 

 be still further increased. 



The establishment of even a small 



