PEDIGREE INHERITANCE. 
405 
so on, to the total heritage of the individual, t h a t 
is to say, each ancestral generation supplies one 
unit, on the average, to the total heritage of the 
individu a 1. The value of the individuality, viz., the removal made 
by the individual in comparison to its ancestors, is equal to the value of 
each generation of its predecessors, is equal to the unit, and is almost nothing, 
as compared with the full series of ancestors or, with the total heritage. 
The only correct representation of the individual 
is such a rectangular parallelogram, the width 
of which is equal to the unit, and whose varying 
length goes on ad infinitum. The individual can also be 
■compared to an endless chain, the first link of w T hich represents the indivi¬ 
duality, the second, the generation of the parents, the third, that of the 
grandparents, and the succeeding links, one of the ascendant ancestral 
generations each. This deduction is shown in the form of a pedigree in the 
iigs. 2 a, 2 b and 2 c, 1 and fig. 8, 2 respectively. 
The above ratio expresses the average probability of the heredity, 
which can be estimated beforehand as a mathematical probability, by the 
experimenter or breeder. If e. g. the following pedigree is given (fig. 4), 3 
in which I == white (or good), II = grey (or moderate) and III == black 
(or bad) qualities, one can anticipate 2*1 white (or good), 8*8 grey (or mo- 
1 Fig. 2 a. — 2, white sire y 2 , 3, black dam y 2 ; the parental generation y 2 + 42 = 1 ; 
1, the individuality of the produce, y 2 white + y 2 black, y 2 + y 2 = 1. 
Fig. 2 b. — 4 — 6, white g. parents, 44 each; 7, black g. dam 44 ; the g. parental gene¬ 
ration 4 X 44 = 1 ; 2, white sire y 2 , 3, grey dam 44 white + 44 black; the parental gene¬ 
ration y 2 + (2 X 44) — 1 ; 1, the individuality of the produce % white + 44 black, % + 
44 = l. 
Fig. 2 c.— 8 — 14, white g. g. parents, 1 / 8 each, 15, black g. g. dam Vs the g. g. parental 
generation 8 X 4/s = 1 ; 4—6, white g. parents, 44 e ac h, 7, grey g. dam Vs white + 1 / 8 black, 
the g. parental generation (3 X 44) + (2 X x / 8 ) = 1 ; 2, white sire y 2 , 3, dam â / 8 white + Vs 
black; the parental generation 44 + 3 /s + Vs = 1 î V the individuality of the produce 
7 /s white + V 8 black, 7 / 8 + Vs = *• 
(Figs 2 a—c, see pag. 386. — The pedigree of the y 2 , % and 7 /s bred produce. 
F 1 , the individuality of the produce, P 1 . the parental, P 2 , the g. parental, P 3 , the g. g. 
parental generations.) 
2 Fig. 3. (See pag. 388.) — The average ratio of inheritance. — P 6 , the g. g. g. g. 
parental generation, 32 x 4 / 32=1 ; P 4 , the g. g. g. parental generation, 16x 1 / 16 = l ; P 3 , the g. 
g. parental generation, 8x 7s=i;^> the g. parental generation, 4x 44 — 1 > Fi, the parental 
generation, 2x 42 = 15 the individuality of the produce = 1. 
9 Fig. 4. (See pag. 388.) — The practical calculation of the average inheritance 
on the ground of a given pedigree. F t , the average produce : P 1? the parental, P 2 , the g. 
parental, P 3 the g. g. parental, P 4 , the g. g. g. parental generations. The ratio of the 
properties I : II : 111 = 21: 33 : 10=2T : 3’3 : 1. 
