Tabulating’ the corresponding quantities for the other sex we find
9 Skeletons. Number* — 22 to 24. Measurements in centimetres.
Femur, F : m1— .38-075, ol = T494, vx = 3'924. Tibia, T : m2 == 29-800, <t2= 1‘576, v2 = 5-289. Humerus, H : m 3 = 27-565, <r3 = 1-109, v5 4-022. Femur and tibia : r12 = 0'8457. Mathematical Contributions to the Theory Evolution. 497 Femur and humerus : r13 = 0"8922. Tibia and humerus : r23 = 0*7277. Index, F /T : in —127-90, 2 ]3 = 3-8937, Vl2 = 3-0444. Index, F /H : in = 138-37, 2 13 = 2-6930, Vi3 = 1-9462. Index, T/H : it3 = 108"36, 223 = 4-1022, Vi3 = 3-7857. (> = 0-6006. Po = 0-3904.
Hence we may conclude as follows :
(i) The absolute lengths of the long bones differ from those of the skull in being very closely correlated.
(ii) The use of indices for the long bones would appear to minimise, rather than, as in the case of the skull, to exaggerate this correlation.
(iii) If we measure, however, organic correlation of the indices by P—Pot we shall find index correlation less than absolute length correlation for both long bones and skull, and in both cases the former comparatively small as compared with the latter.
(iv) The results for the 24 female skeletons, although based on but few data, serve on the whole to confirm the male results.*
(6.) From the above examples it will be seen that the method, winch judges of the intensity of organic correlation by the reduction of all absolute measures to indices, the denominators of which are some one absolute measurement, is not free from obscurity; for this method would give the major portion of the observed index correlation had the parts of the animal been thrown together entirely at random, i.e., if there were no organic correlation at all. The following additional remarks may be of interest. The results (iv)—(vi) show us that the correlation coefficients of indices are functions, not only of the correlation coefficients of absolute measurements, but also of the coefficients of variation of the latter measurements. Hence,
- The facfc that the male is more variable in height-sitting, in femur, and in
tibia than the female, while she appears to be more variable than he is in stature led me to prophesy, in my paper on “ Variation in Man and Woman,” that the emale would be found to be more closely correlated in the bones forming stature than the male. This appears to be the case for the femur and tibia of Ainos
