Showing papers by "University of Oviedo published in 1964"

Genetics of the a-b ridge count on the human palm.

Abstract: In the analysis of the morphology of epidermal ridges the ' deltas ' or ' triradii ' appear as very important elements. A triradius can be defined as the meeting point of three ridges called radiants. On the palm there are normally four triradii, one at the base of each finger, called u, b, c and d, beginning with the one under the index finger, and another triradius known as t near the base of the fourth metacarpal bone or at some point on its axis. The study of the degree of separation between tritadii can supply interesting data on ridge configuration. The number of ridges between two triradii seems a suitable measure of this separation for it is independent of hand size. This is specially important in the present paper which involves parent-child comparisons with significant differences in hand sizes. For this reason, the direct measurement is obviously unsuitable, since it is not easy to find an appropriate correction factor for the varying hand sizes. Further, we must not forget another possible source of error, namely, that due to the variability in pressure and in spreading the hand on obtaining the prints. In this paper the ridge count between triradii a and b is analysed. The a-b count is obtained by counting the epidermal ridges crossing or touching a fine straight line joining both triradii. Nascent ridges and triradial points are excluded in making the count. As an individual trait we use the value resulting from the addition of the a-b counts of the two hands.