INHKKITANCK, WITH SPECIAL KEFEKENCE TO .MENDEL'S LAWS. 



8:5 



as we pass away from the mean of the population the regression gets less and less, 

 becoming absolutely zero when we take two pure allogenic parents. Just as the 

 regression is reduced when we emphasise the allogenic constitution of the parents, it 

 is increased when we emphasise the non -allogenic elements. 



To illustrate these points 1 have drawn a diagram for n = 9 of the contour lines of 



\ \ 



\ v y 





\N 







Mdndelian 



Gcltonian 



Str 



Hyperbolas 



ight. Lir 



ies 



\\ 

 \ 



\\ 



\ 

 \ \ 



\ 



A 9 



Is 



\ \ 

 \ 



\ 





*,' 







o o 

 y% a 



I* 



T3 " 

 I, 



V 



\ X 



\ 



\ 





< 



1, 



A 



\ 



M 



' ..... 2. 3 5 



7 8 9 



^ Number of Allogenic Couplets in Father. 



Midparental contours. 



the regression surface as a plane and a hyperboloid. The area ABCD contains all 

 possible parents; 999 out of 1000 random matings fall in the loop abed; 99 out of 

 100 random mating within the loop a'b'c'd', which has been carried right round to 

 mark that it excludes matings in which both parents have no allogenic couplets. The 



M 2 



