Morphological Studies of Head Hair in Ainu.

By using randomly chosen hair samples of 590 strands, consisting of 5 strands on an average for each region of the frontal, parietal, and occipital, from 40 individuals of both sexes of the Ainu, the metrical traits of five objects (length of major axis, length of minor axis, index, size, and area) and the medulla properties were investigated about various phases of the head hairs in this study. 1. Hair type, expressed in an index, is referred to as long elliptic form in each region of both sexes after maturity. 2. Differences among individual means of 20 persons in both sexes are highly significant for all five objects. 3. Indices of each region of females invariably show a slightly higher value than those of males. Regional differences are insignificant between means of the five objects, but sex differences of the same region are significant in the length of major axis and in the size of the occipital region. 4. Age differences between the first and second age groups are significant in each object, without index, of the parietal region of both sexes, and besides these age differences are significant in the length of minor axis, size, and area of the frontal and occipital regions of only females. Meanwhile, sex differences between the same age groups, excluding the third age group, show insignificance in any objects. 5. Of medulla indices, regional differences are significant in both sexes between the frontal and the parietal regions, and in males between the frontal regions, as well. Sex differences on the medulla index are insignificant in the three regions. 6. On the occurrences of the medullary types, generally, the discontinuous type shows in a higher frequency, and the absent type occupies next rank to the above type, and further the continuous type occurs in a lower frequency. In analysing regional, sex, and age differences, there are a certain peculiarity among proportions of the medullary types. 7. Between hair sizes of the same medullary types, regional differences are not estimated. But significant sex differences between the same medullary types are verified statistically both in the continuous types of the frontal region and in the absent types of the occipital region. Differences between hair sizes of each medullary types in each region of both sexes are attested to be significant in all except for a few instances. 8. In discussing hair properties of the Ainu to the other races, the differences among races seem to be significant in various phases of the cross sections and medullations of the hair shafts.