v PATTERNS : THEIR OUTLINES AND CORES 6 7
and by other secondary matters such as the number of ' turns in the whorled patterns, and the relative dimensions of their different parts. The first need to be satisfied, before it could become possible to base the classification upon a more sure foundation than that of general appearance, was to establish a well - defined point or points of reference in the patterns. This was done by utilising the centres of the one or two triangular plots (see Plate 4, Fig 8, 2, 3) 4) which are found in the great majority of patterns, and whose existence was pointed out by Purkenje, but not their more remote cause,
which. is as follows
The ridges, as was shown in the diagram (Plate 3) of the palm of the hand, run athwart the fingers in rudely parallel lines up to the last joint, and if it were not for the finger-nail, would apparently continue parallel up to the extreme finger-tip. But the presence of the nail disturbs their parallelism and squeezes them downwards on both sides of the finger. (See Fig. 8, 2.) Consequently, the ridges that run close to the tip are greatly arched, those that successively follow are gradually less arched until, in some cases, all signs of the arch disappear at about the level of the first joint (Fig. 8, 1). Usually, however, this gradual transition from an arch to a straight line fails to be carried out, causing a break-in the orderly sequence, and a consequent interspace (Fig. 8, 2). The topmost boundary of the interspace . is formed by the lowermost arch, and its lowermost boundary by the topmost straight ridge. But an equally large number of
