1910-11.] The Inheritance of Complex Growth Forms. 
251 
XI. — The Inheritance of Complex Growth Forms, such as Stature, 
on Mendel’s Theory. By John Brownlee, M.D., D.Sc. 
(MS. received May 16, 1910. Read same date.) 
The inheritance of complexes is of great interest. The manner in which 
this arises on a Mendelian basis can be most easily seen by the consideration 
of a simple case. Let two races of different stature mix in equal numbers. 
Let for simplicity stature depend on two elements (a, a), (c, c) in one race, 
and on (b, b), (d, d) corresponding elements in the other. Then the per- 
manent race obtained by free mating without any special selection of one 
parent or another will consist of the following proportions : — 
a , a 
a, a 
a , a 
a , b 
a, b 
a , b 
1 
+ 2 
+ 1 
+ 2 
+ 4 
+ 2 
c, c 
c , a 
d , d 
c, c 
c, d 
d, d 
b, b 
+ 2 
b, b 
+ 1 
b , b j 
c, c 
c, d 
d, d 1 
Now two factors may come into play : either dominance may not exist 
and the hybrid be a blend, or, on the other hand, dominance may determine 
the result of the mating. If dominance does not exist we may rearrange 
the elements according as they contain one or more element from each 
original race. On this hypothesis we have the following groups : — 
a, a 
a, a 
a , b 
b , b 
b, b 
1 
c , c 
2 
c , d 
4 
c, d 
2 
c, d 
1 
d, d 
a, b 
a , a 
a, b 
2 
c, e 
1 
d , d 
2 
d , d 
b, b 
1 
Totals, 
c, c 
4 6 
4 
1 
That is, stature tends to be graded according to the ordinary point 
binomial, it being granted probable that each group as above placed has 
essentially the same stature. 
If dominance, however, exist it is a reasonable assumption that each 
race may supply an equal number of dominant elements (in this case one 
