348 
A Study of the Hand 
or there is no sensible difference between the distal phalanges of i"ight and left 
hand except in the case of the thumb. Applying the same test — means for pairs 
of corresponding bones on right and left hands of same individual — we find that in 
the 19 cases dealt with the right is larger in 13 cases, in a 14th case the means 
are equal ; in 5 cases only is the left larger. In not one of these 5 cases is the 
ditference of the means more than a small fraction of the probable error of the 
difference, while in 9 out of the 13 cases in which the right-hand bone is larger 
the difference is as large as the probable error. We must therefore conclude 
that : 
Judged by the skeleton the right hand is larger than the left, but the pre- 
ponderance of the right hand decreases as we pass downwards from the metacarpal 
bones to the distal phalanges, where it vanishes. This is in accordance with our 
result for finger joints*, and in disagreement with Dr Pfitzner's conclusions from 
the same data ; he considers that there is no quantitative difference between right 
and left for the simple anatomical parts of the hand skelet(m. 
Turning to absolute variability, we find the standard deviation larger in 11 cases 
for the right hand, 5 for the left and in 3 exactly equal from the above Table. 
Taking only cases in which we have bones from the two hands of the same 
individual we have 7 cases of right preponderance, 9 of left, and 3 of equality. 
Lastly, considering relative variability we have from the above Table 11 cases 
in which the right hand has a greater coefficient of variation and 8 cases in which 
the left preponderates. Dealing with the smaller number of cases in which we 
have pairs from both hands, we find the order inverted and 9 cases for the right 
and 10 for the left. 
The average coefficient of variation for pairs from both hands is 6'14 for the 
right and 6'06 for the left. It would be unwise to base any statement as to the 
relative variability of the hands on such a slight difference as this, considering 
that we are dealing with only 37 to 40 pairs of hands. In the finger measure- 
ments the left hand was foimd slightly more variable than the right, but it 
was remarked : that " the divergence is not one on which real stress can be laid 
considering the probable error of the coefficient of variationf." 
We can therefore merely state that we find no sensible difference in variability 
for the two hands. 
Turning now to relative variability (coefficients of variation) of the respective 
fingers, we note that in the case of the first joints of the fingers on the living 
subject the order of variability for the left hand was : 
(i) Little Finger, (ii) Ring Finger, (iii) Index Finger, (iv) Middle 
Finger. 
If we take the average variability of all the phalanges we have for our present 
data : 
' R. S. Proc. Vol. 65, p. 129. 
t Loc. cit. footnote, p. 129. 
