3. _Oblique Stria._--A solitary line runs from one or other of the two sides of the finger, pa.s.sing obliquely between the transverse curves in 1, and ending near the middle.
4. _Oblique Sinus._--If this oblique line recurves towards the side from which it started, and is accompanied by several others, all recurved in the same way, the result is an oblique sinus, more or less upright, or horizontal, as the case may be. A junction at its base, of minute lines proceeding from either of its sides, forms a triangle.
This distribution of the furrows, in which an oblique sinus is found, is by far the most common, and it may be considered as a special characteristic of man; the furrows that are packed in longitudinal rows are, on the other hand, peculiar to monkeys. The vertex of the oblique sinus is generally inclined towards the radial side of the hand, but it must be observed that the contrary is more frequently the case in the fore-finger, the vertex there tending towards the ulnar side. Scarcely any other configuration is to be found on the toes. The ring finger, too, is often marked with one of the more intricate kinds of pattern, while the remaining fingers have either the oblique sinus or one of the other simpler forms.
[Ill.u.s.tration: PLATE 12.
FIG. 19. THE STANDARD PATTERNS OF PURKENJE.]
5. _Almond._--Here the oblique sinus, as already described, encloses an almond-shaped figure, blunt above, pointed below, and formed of concentric furrows.
6. _Spiral._--When the transverse flexures described in 1 do not pa.s.s gradually from straight lines into curves, but a.s.sume that form suddenly with a more rapid divergence, a semicircular s.p.a.ce is necessarily created, which stands upon the straight and horizontal lines below, as it were upon a base. This s.p.a.ce is filled by a spiral either of a simple or composite form. The term "simple" spiral is to be understood in the usual geometric sense. I call the spiral "composite" when it is made up of several lines proceeding from the same centre, or of lines branching at intervals and twisted upon themselves. At either side, where the spiral is contiguous to the place at which the straight and curved lines begin to diverge, in order to enclose it, two triangles are formed, just like the single one that is formed at the side of the oblique sinus.
7. _Ellipse_, or _Elliptical Whorl_.--The semicircular s.p.a.ce described in 6 is here filled with concentric ellipses enclosing a short single line in their middle.
8. _Circle_, or _Circular Whorl_.--Here a single point takes the place of the short line mentioned in 7. It is surrounded by a number of concentric circles reaching to the ridges that bound the semicircular s.p.a.ce.
9. _Double Whorl._--One portion of the transverse lines runs forward with a bend and recurves upon itself with a half turn, and is embraced by another portion which proceeds from the other side in the same way.
This produces a doubly twisted figure which is rarely met with except on the thumb, fore, and ring fingers. The ends of the curved portions may be variously inclined; they may be nearly perpendicular, of various degrees of obliquity, or nearly horizontal.
In all of the forms 6, 7, 8, and 9, triangles may be seen at the points where the divergence begins between the transverse and the arched lines, and at both sides. On the remaining phalanges, the transverse lines proceed diagonally, and are straight or only slightly curved."
(He then proceeds to speak of the palm of the hand in men and in monkeys.)
CHAPTER VI
PERSISTENCE
The evidence that the minutiae persist throughout life is derived from the scrutiny and comparison of various duplicate impressions, one of each pair having been made many years ago, the other recently. Those which I have studied more or less exhaustively are derived from the digits of fifteen different persons. In some cases repeated impressions of one finger only were available; in most cases of two fingers; in some of an entire hand.
Altogether the whole or part of repeated impressions of between twenty and thirty different digits have been studied. I am indebted to Sir W. J.
Herschel for almost all these valuable data, without which it would have been impossible to carry on the inquiry. The only other prints are those of Sir W. G----, who, from curiosity, took impressions of his own fingers in sealing-wax in 1874, and fortunately happened to preserve them. He was good enough to make others for me last year, from which photographic prints were made. The following table gives an a.n.a.lysis of the above data.
It would be well worth while to hunt up and take the present finger prints of such of the Hindoos as may now be alive, whose impressions were taken in India by Sir W. J. Herschel, and are still preserved. Many years must elapse before my own large collection of finger prints will be available for the purpose of testing persistence during long periods.
The pattern in every distinct finger print, even though it be only a dabbed impression, contains on a rough average thirty-five different points of reference, in addition to its general peculiarities of outline and core. They consist of forkings, beginnings or ends of ridges, islands, and enclosures. These minute details are by no means peculiar to the pattern itself, but are distributed with almost equal abundance throughout the whole palmar surface. In order to make an exhaustive comparison of two impressions they ought to be photographically enlarged to a size not smaller than those shown in Plate 15. Two negatives of impressions can thus be taken side by side on an ordinary quarter-plate, and any number of photographic prints made from them; but, for still more comfortable working, a further enlargement is desirable, say by the prism, p. 52. Some of the prints may be made on ferro-prussiate paper, as already mentioned pp. 51, 53; they are more convenient by far than prints made by the silver or by the platinum process.
Having placed the enlarged prints side by side, two or three conspicuous and convenient points of reference, whether islands, enclosures, or particularly distinct bifurcations, should be identified and marked. By their help, the position of the prints should be readjusted, so that they shall be oriented exactly alike. From each point of reference, in succession, the spines of the ridges are then to be followed with a fine pencil, in the two prints alternately, neatly marking each new point of comparison with a numeral in coloured ink (Plate 13). When both of the prints are good and clear, this is rapidly done; wherever the impressions are faulty, there may be many ambiguities requiring patience to unravel.
At first I was timid, and proceeded too hesitatingly when one of the impressions was indistinct, making short alternate traces. Afterwards on gaining confidence, I traced boldly, starting from any well-defined point of reference and not stopping until there were reasonable grounds for hesitation, and found it easy in this way to trace the unions between opposite and incompletely printed ends of ridges, and to disentangle many bad impressions.
An exact correspondence between the _details_ of two minutiae is of secondary importance. Thus, the commonest point of reference is a bifurcation; now the neck or point of divergence of a new ridge is apt to be a little low, and sometimes fails to take the ink; hence a new ridge may appear in one of the prints to have an independent origin, and in the other to be a branch. The _apparent_ origin is therefore of little importance, the main fact to be attended to is that a new ridge comes into existence at a particular point; _how_ it came into existence is a secondary matter. Similarly, an apparently broken ridge may in reality be due to an imperfectly printed enclosure; and an island in one print may appear as part of an enclosure in the other. Moreover, this variation in details may be the effect not only of imperfect inking or printing, but of disintegration due to old age, which renders the impressions of the ridges ragged and broken, as in my own finger prints on the t.i.tle-page.
Plate 11, Fig. 18 explains the nature of the apparent discrepancies better than a verbal description. In _a_ a new ridge appears to be suddenly intruded between two adjacent ones, which have separated to make room for it; but a second print, taken from the same finger, may have the appearance of either _b_ or _c_, showing that the new ridge is in reality a fork of one or other of them, the low connecting neck having failed to leave an impression. The second line of examples shows how an enclosure which is clearly defined in _d_ may give rise to the appearance of broken continuity shown in _e_, and how a distinct island _f_ in one of the prints may be the remnant of an enclosure which is shown in the other.
These remarks are offered as a caution against attaching undue importance to disaccord in the details of the minutiae that are found in the same place in different prints. Usually, however, the distinction between a fork and the beginning of a new ridge is clear enough; the islands and enclosures are also mostly well marked.
[Ill.u.s.tration: PLATE 13.
FIG. 20. V. H. H-D aet. 2-1/2 in 1877, and again as a boy in Nov. 1890.]
Plate 13 gives impressions taken from the fingers of a child of 2-1/2 years in 1877, and again in 1890, when a boy of 15. They are enlarged photographically to the same size, and are therefore on different scales.
The impressions from the baby-hand are not sharp, but sufficiently distinct for comparison. Every bifurcation, and beginning or ending of a ridge, common to the two impressions, is marked with a numeral in blue ink. There is only one island in the present instance, and that is in the upper pair of prints; it is clearly seen in the right hand print, lying to the left of the inscribed number 13, but the badness of the left hand print makes it hardly decipherable, so it is not numbered. There are a total of twenty-six good points of comparison common to the upper pair of prints; there are forty-three points in the lower pair, forty-two of which appear in both, leaving a single point of disagreement; it is marked A on the fifth ridge counting from the top. Here a bifurcated ridge in the baby is filled up in the boy. This one exception, small though it be, is in my experience unique. The total result of the two pairs of prints is to afford sixty-eight successes and one failure. The student will find it well worth his while to study these and the following prints step by step, to satisfy himself of the extraordinarily exact coincidences between the two members of either of the pairs. Of course the patterns generally must be the same, if the ridges composing them are exactly alike, and the most cursory glance shows them to be so.
[Ill.u.s.tration: PLATE 14.
FIG. 21.]
Plate 14, Fig. 21 contains rather less than a quarter of each of eight pairs that were published in the _Phil. Trans._ memoir above alluded to.
They were there enlarged photographically to twice their natural size, which was hardly enough, as it did not allow sufficient s.p.a.ce for inserting the necessary reference numbers. Consequently they have been again considerably enlarged, so much so that it is impossible to put more than a portion of each on the page. However, what is given suffices. The omitted portions may be studied in the memoir. The cases of ~1~ and ~2~ are prints of different fingers of the same individual, first as a child 8 years old, and then as a boy of 17. They have been enlarged on the same scale but not to the same size; so the print of the child includes a larger proportion of the original impression than that of the boy. It is therefore only a part of the child"s print which is comparable with that of the boy. The remaining six cases refer to four different men, belonging to three quite different families, although their surnames happen to have the same initial, H. They were adults when the first print was made, and from 26 to 31 years older on the second occasion. There is an exact agreement throughout between the two members of each of the eight several couplets.
In the pair 2. A. E. H. Hl., there is an interesting dot at the point ~4~ (being an island it deserved to have had two numbers, one for the beginning and one for the end). Small as it is, it persists; its growth in size corresponding to the growth of the child in stature.
[Ill.u.s.tration: PLATE 15.
FIG. 22. RIGHT FOREFINGER OF SIR W. J. H. in 1860 and in 1888.]
FIG. 23. DISTRIBUTION OF THE PERIODS OF LIFE, to which the evidence of persistency refers.
+-----------------------------------------------------------------------+AgeAgeAges, 0--80 years.Persons.atIntervalatfirstinsecondprintyearsprint10 20 30 40 50 60 70----------------------------------------------------------------H. H--d21315----+--A. H--l41216---+---J. H--l81321--+----+E. H--l101323----+--W.J. H--l263056--+----+----+--R.F. H--n263157--+----+----+---N.H. T--n272855-+----+----+--F.H. H--t272653-+----+----+-W. G--e621779----+----+-----------------------------------------------------------------------+
For the sake of those who are deficient in the colour sense and therefore hardly able, if at all, to distinguish even the blue numerals in Figs. 20, 21, I give an eleventh example, Plate 15, Fig. 22, printed all in black.
The numerals are here very legible, but s.p.a.ce for their insertion had to be obtained by sacrificing some of the lineations. It is the right fore-finger of Sir W. Herschel and has been already published twice; first in the account of my lecture at the Royal Inst.i.tution, and secondly, in its present conspicuous form, in my paper in the _Nineteenth Century_. The number of years that elapsed between the two impressions is thirty-one, and the prints contain twenty-four points of comparison, all of which will be seen to agree. I also possess a later print than this, taken in 1890 from the same finger, which tells the same tale.
The final result of the prints in these pages is that they give photographic enlargements of the whole or portions of eleven couplets belonging to six different persons, who are members of five unrelated families, and which contain between them 158 points of comparison, of which only one failed. Adding the portions of the prints that are omitted here, but which will be found in the _Phil. Trans._, the material that I have thus far published contains 389 points of comparison, of which one failed. The details are given in the annexed table:--
+-----------------------------------------------------------------------+OrderInitials.DigitAgeDates ofYearsTotal pointsinofatthe twoelapsedof agreement intherightdateprints.between-------------------Figs.hand.of--------the twoFigs. 20Figs. 20,firstprints.and 21.22, and inprint.1st 2ndPh. Trans.----------------------------------------------------------------FIG. 201.V. H. Hd.Fore2-1/21877-901326262.V. H. Hd.Ring2-1/21877-90134242FIG. 211.A. E. H. Hl.Fore81881-90911332.A. E. H. Hl.Ring81881-9095363.N. H. Tn.Fore281862-90286274.N. H. Tn.Middle281862-902810365.F. K. Ht.Fore281862-882612556.R. F. Hn.Middle311859-90316277.W. J. Hl.Thumb301860-90309508.W. J. Hl.Ring311859-9031632FIG. 221.W. J. Hl.Fore311859-90312424---------------------------------------------------------------------Total points of agreement157388Do. of disagreement11+-----------------------------------------------------------------------+
It is difficult to give a just estimate of the number of points of comparison that I have studied in other couplets of prints, because they were not examined as exhaustively as in these. There were no less than one hundred and eleven of them in the ball of the thumb of the child V. H.
Hd., besides twenty-five in the imperfect prints of his middle and little fingers; these alone raise the total of 389 to 525. I must on the whole have looked for more than 700 points of comparison, and have found agreement in every single case that was examined, except the one already mentioned in Fig. 20, of a ridge that was split in the child, but had closed up some few years later.
The prints in the two plates cover the intervals from childhood to boyhood, from boyhood to early manhood, from manhood to about the age of 60, and another set--that of Sir W. G.--covers the interval from 67 to 80.
This is clearly expressed by the diagram (Plate 15, Fig. 23). As there is no sign, except in one case, of change during any one of these four intervals, which together almost wholly cover the ordinary life of man, we are justified in inferring that between birth and death there is absolutely no change in, say, 699 out of 700 of the numerous characteristics in the markings of the fingers of the same person, such as can be impressed by them whenever it is desirable to do so. Neither can there be any change after death, up to the time when the skin perishes through decomposition; for example, the marks on the fingers of many Egyptian mummies, and on the paws of stuffed monkeys, still remain legible. Very good evidence and careful inquiry is thus seen to justify the popular idea of the persistence of finger markings, that has. .h.i.therto been too rashly jumped at, and which wrongly ascribed the persistence to the general appearance of the pattern, rather than to the minutiae it contains. There appear to be no external bodily characteristics, other than deep scars and tattoo marks, comparable in their persistence to these markings, whether they be on the finger, on other parts of the palmar surface of the hand, or on the sole of the foot. At the same time they are out of all proportion more numerous than any other measurable features; about thirty-five of them are situated on the bulb of each of the ten digits, in addition to more than 100 on the ball of the thumb, which has not one-fifth of the superficies of the rest of the palmar surface. The total number of points suitable for comparison on the two hands must therefore be not less than one thousand and nearer to two; an estimate which I verified by a rough count on my own hand; similarly in respect to the feet. The dimensions of the limbs and body alter in the course of growth and decay; the colour, quant.i.ty, and quality of the hair, the tint and quality of the skin, the number and set of the teeth, the expression of the features, the gestures, the handwriting, even the eye-colour, change after many years. There seems no persistence in the visible parts of the body, except in these minute and hitherto too much disregarded ridges.
It must be emphasised that it is in the minutiae, and _not_ in the measured dimensions of any portion of the pattern, that this remarkable persistence is observed, not even if the measurements be made in units of a ridge-interval. The pattern grows simultaneously with the finger, and its proportions vary with its fatness, leanness, usage, gouty deformation, or age. But, though the pattern as a whole may become considerably altered in length or breadth, the number of ridges, their embranchments, and other minutiae remain unchanged. So it is with the pattern on a piece of lace.
The piece as a whole may be stretched in this way, or shrunk in that, and its outline altogether altered; nevertheless every one of the component threads, and every knot in every thread, can easily be traced and identified in both. Therefore, in speaking of the persistence of the marks on the finger, the phrase must be taken to apply princ.i.p.ally to the minutiae, and to the general character of the pattern; not to the measure of its length, breadth, or other diameter; these being no more constant than the stature, or any other of the ordinary anthropometric data.
CHAPTER VII