value. Even the tabulation of citizens
according to their social standing or "civic worth" gives the same
sort of thing. This has been brought out nicely in Galton's discussion
of Booth's classification of the population of London.

TABLE I

_Coefficients of Variability of Certain Human Traits_

Adult Stature 3.6 to 4.0
Length at Birth 5.8 to 6.5
Length of Limb Bones 4.5 to 5.5
Cephalic Index 3.7 to 4.8
Skull Capacity 7.0 to 8.0
Weight (University Students) 10.0 to 11.0
Weight at Birth 14.2 to 15.7
Weight of Brain 7.0 to 10.6
Weight of Heart 17.4 to 20.7
Weight of Liver 14.3 to 22.2
Weight of Kidney 16.8 to 22.5
Lung Capacity 16.6 to 20.4
Squeeze of Hand 13.4 to 21.4
Strength of Pull 15.0 to 22.6
Swiftness of Blow 17.1 to 19.4
Dermal Sensitivity 35.7 to 45.7
Keenness of Eyesight 28.7 to 34.7

It is not so easy to answer the question whether mutations or true
variations are occurring frequently in the human species. Usually it
is impossible to distinguish between an extreme fluctuation and a true
variation without experimental test and the observation of the
behavior of the varying trait through several generations. In most
instances this has been impossible with human beings. From collateral
evidence it seems quite probable that man is mutating with
considerable frequency, especially with respect to psychic traits.

The evolution of the race could be directed more easily and permanent
results attained more rapidly through taking advantage of valuable
mutations than in any other way. A race truly desiring to progress
would foster carefully anything resembling mutation in a favorable
direction. As a matter of fact, however, our social custom leads us to
look with disfavor upon most youthful traits that seem unusual or out
of the ordinary. It would be difficult to devise a system of
"education" which could more effectively repress than does our own the
development of unusual mental traits. In this connection "abnormal" or
"eccentric" may often m