Racial aspects of the a-b ridge count on the human palm.

This paper deals with racial differences in the a-b ridge count. From the data of 75 series it is found that the Whites and Blacks are showing only little variability. In White populations the a-b ridge counts vary between 80 and 86 ridges, in Black populations (having generally lower values) between 74 and 80. The series from the Indian subcontinent are characteristic by very low values and a great variability, which ranges between 68 and 80. High values and also a great variability were observed among American Indians (80-90). The hitherto known data for Mongoloid populations from Asia are insufficient for detailed evaluations.