Ridge Tracing and Counting Whorl Patterns
1. Ridge tracing (For purposes of tracing, the extreme left delta and
extreme right delta are of concern. Where there is a third delta, such
as may be present in the center of the pattern, that delta is not
counted; Figure 3.120.)
a. Establish deltas.
b. Starting at the left delta, trace ridges, moving outward away from the center of the pattern to where the ridge ends. Continue tracing until the point nearest or opposite the extreme right delta is reached.
c. If the ridge bifurcates, the lower branch is followed.
d. Examine other apparent ridge endings in the pattern to ensure that the ridge actually ends and is not caused by other factors such as improper inking, the presence of debris, and the like.
e. The number of ridges between the tracing ridge and the right delta is counted.
Inner (I): Three or more ridges inside the right delta Meet (M): Fewer than three inside or outside right delta (0, 1, 2) Outer (O): Three or more ridges outside the right delta
g. In accidental and double loop whorls, when the tracing passes inside of the right delta, stop at the nearest point to the right delta on the upward trend.
Note: Whorl tracing will never begin on a type line.
2. Ridge counts in whorls:
a. Used only in some extensions of classifications.
Figure 3.133 Whorl ridge tracing illustrations: (a) Top, double loop/inner trace value, (b) Bottom left, plain/outer trace value, (c) Bottom right, central pocket loop/inner trace value.
i. Count from the left delta to core on right hand.
ii. Count from the right delta to core on left hand.
c. If more than two deltas are present, use the one on the proper side and closest to the core (Figure 1.134).
The Palm Print
As with fingerprints, palms can be used for purposes of individualization, identification, and exclusion. Though not as many rules apply to the palm, the process whereby the palm is used for comparison, identification, and
individualization is the same. The palm is obviously labeled differently as a number of different palms possess a variety of creases and parts. The palm itself contains ridge characteristics such as deltas, bifurcations, and ending ridges but differs in the main parts. There are three primary divisions of the palm (Figure 3.135).
There are also various creases in the palm that are used for descriptive purposes (Figure 3.136).
- • Interdigital
- • Thenar
- • Hypothenar
Figure 3.135 Divisions of the palm.
Figure 3.136 Creases in the palm.
- 1. Define a loop pattern.
- 2. What are the essentials of a loop pattern?
- 3. What structures may be a delta?
- 4. What are the rules governing the choice between two deltas?
- 5. What are the shoulders of a loop?
- 6. What is meant by an appendage spoiling a loop?
- 7. Define the plain arch pattern.
- 8. What is the “crest” of an arch pattern?
- 9. What is another name for an arch pattern?
- 10. Will there be deltas, cores, recurves, or type lines in the plain arch pattern?
- 11. Define the tented arch pattern.
- 12. What are the three types of tented arches?
- 13. What is the test for an upthrust?
- 14. Can the converging of two ridges be considered to form a recurve?
- 15. What are the four types of whorl patterns?
- 16. What is the general definition applying to all whorl patterns?
- 17. What is the delta-to-delta test for a plain whorl?
- 18. What is the inner line of flow and how is it used?
- 19. Must both loops in a double loop whorl have a ridge count?
- 20. What type of pattern is formed by a combination of an arch and a loop?
- 21. What are the types of accidental whorl patterns?