106 LABORATORY MANUAL OF ANTHROPOMETRY 



except in the bones of carpus and tarsus, whose proportions, taken a 

 bone at a time, are frequently found significant, the points of comparison 

 are found in the dimensions of the palm as a whole, or the relative lengths 

 of entire fingers, while little or nothing is to be expected from single bones. 

 It is thus frequently necessary to use as data the total lengths and breadths 

 of several bones together, in which work the exact identity of every 

 phalanx is of the utmost importance. 



For convenience of treatment the proportions of the hand as a whole, 

 or without the carpus, and those of the separate carpals, are here treated 

 separately, and in the order mentioned. 



I. THE PROPORTIONS OF THE HAND (WITHOUT THE CARPUS) 



This part consists of the 14 phalanges, together with the 5 meta- 

 carpals, 19 bones in all; their measurements, used either separately or 

 in combination, consist of lengths, breadths, and depths (dorso-ventrally) . 



1 . Lengths. There are two possible lengths of phalanx or a metacarpal ; 

 the anatomical or maximum length, and the physiological. The first 

 includes all processes or ridges which may be found prolonging the articu- 

 lations, and this length is taken either by the anthropometric board or by 

 a slide compass with flat points. 



The ordinary type of osteometric board is too large and heavy for all 

 except the metacai pals' or the basal phalanges, and for this sort of work 

 a much smaller size should be constructed, delicate enough to measure 

 accurately, at least to half-millimeters, a bone the size of a terminal 

 phalanx. 



The physiological length, or that length which is actually effective 

 when the articulations are closed together as in life, is that found by 

 measuring the length from the center of the depression of the articular 

 surface at one end by that of the other. This seems, and probably is, 

 the best one to use in calculations requiring the length of an entire finger, 

 since, when put together in the natural manner, the length contributed 

 by each piece would be its physiological, and not its maximum length. 



2. Breadths. The usual practice in ascertaining the breadth of a 

 given phalanx, with its difference in caliber, and hence of breadth, at 

 various points, is to measure the exact breadth at three places, across 

 the two epiphyses and the middle, and average all three by adding them 

 together and dividing by 3. 



3. Depths (Heights). This measure, taken dorso-ventrally through a 

 phalanx, at right angles to the previous one, is usually taken in the same 

 way as the last, by the average of three measures, taken in the same 

 places as the last. 



4. Calibers. The caliber of the separate phalanges is a set of measures 

 that will become important in the future without much doubt, but has 

 not been employed thus far, probably owing to the technical difficulty of 

 making a sufficiently accurate measurement to be of much discriminative 



