360 
A Study of the Hand 
(vii) Generally there is a " rule of neighbourhood," i.e. any bone is more 
closely correlated with a second of the same series than with any other from which 
it is separated by that second. Speaking roundly this is true for both lateral and 
longitudinal series ; but there are apparently significant deviations from this rule, 
the most notable of which are, perhaps, those of the distal phalanges which on all 
the fingers of both hands tend to be more highly correlated with the metacarpal 
bones or the proximal phalanges than with the middle phalanges. The middle 
phalanges, however, obey the general rule. 
(viii) The lower bones of the marginal members tend on the whole to be 
most variable ; thus the thumb and little finger are the most variable members 
and the middle and distal phalanges the most variable bones. The middle 
phalanx is, however, more variable than the distal, and there are individual 
exceptions to the rule noted in the body of this paper. 
On the whole our sparse data seem to indicate a regular and continuous distri- 
bution of both variation and correlation folh^wing local position for the bones of 
the hand, and one is strongly impelled to believe that a knowledge of this syste- 
matic distribution obtained from adequate data would reveal much that is yet 
obscure to us in interdigital relationship, and in the nature of the transition from 
homotypic to organic correlations. 
