PHILOSOPHICAL TRANSACTIONS. 
I. MaUiematlcal Contrilmtions to the Theory of Evolution. —XI. On the Influence 
of Natural Selection on the Variahility and Correlation of Organs. 
By Karl Pearson, F.R.S., University College, London. 
Eeceived December 20, 1901,—Eead January 23, 1902. 
Contents. 
(1) Introductory. On the influence of selection upon correlation. 
(2) On the fundamental theorem in multiple correlation. 
{(i) i\Iean value of one varial)le and its variability when - 1 other variables are absolutely 
fixed. 
(0 Correlation of two variables when n - 2 other variables are absolutely fixed. 
(3) General theorem in selection. 
With normal correlation selection of size is uninfluenced by selection of variability . . . . 
(4) Distinction between directly and indirectly selected characters. 
(5) Influence of selection of organ A on the mean and variability of B, and on the correlation of 
A and B. 
(6) Influence of selection of organ A on the correlation of organs B and C. 
lUusfrafions I. to IV. . 
(7) Influence of selection of organs A and B on organs C and D and on their relation to A and B . 
(8) Illustration I. Influence of selection of long bones of the leg on the long bones of the arm . 
Illustration II. Influence of selection of femur and humerus on the stature. 
Illustration III Influence of selection of stature in modifying femur and humerus . . . . 
(9) Application to problems in heredity. 
Illustration I. Influence on direct heredity of the selection of parents. 
Illustration II. Influence on collateral heredity of a selection of parents. 
Illustration III. Influence of selecting two organs in parent on the correlation of the same 
organs in the offspring. 
(10) Selective correlation coefficient and how it directly arises in the case of selection. 
(11) On the probability of survival and the surface of survival-rates. 
(12) Survival-rate curve for selection of one organ. 
Illustration. Death-rate which would reduce the cephalic index of the French to that of the 
Xaqada race.. 
(13) Surface of survival-rates for selection of two organs. 
(14) Illustration. Selection of the Aino, as far as femur and humerus are concerned, from the French 
and vice versa ; constants and diagram ._ . .. 
Positive and negative selection.'. 
(15) General consideration of the surface of survival-rates. Types of death-rate.. . 
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^OL. CC.—A 321. 
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21.11.02 
