teristic—namely, the pigmentation of the hair and eyes—for more specific results. There are three reasons which compel us to take this action. In the first place, the coloration of the hair and eyes appears to be less directly open to disturbance from environmental influences than is the skin, and variations in shading may be at the same time more easily and delicately measured. Secondly, the color or, if you please, the absence of color, in the hair and eyes is more truly peculiar to the European race than is the lightness of its skin. There are many peoples in Europe who are darker skinned than certain tribes in Asia or the Americas; but there is none in which blondness of hair and eyes occurs to any considerable degree. It is in the flaxen hair and blue eye that the peculiarly European type comes to its fullest physical expression. This at once reveals the third inducement for us to focus our study upon these apparently subordinate traits, Europe alone of all the continents is divided against itself. We find blondness in all degrees of intensity scattered among a host of much darker types. A peculiar advantage is herein made manifest. Nowhere else in the world are two such distinct varieties of man in such intimate contact with one another. From the precise determination of their geographical distribution we may gain an insight into many interesting racial events in the past.
The first general interest in the pigmentation of the hair and eyes in Europe dates from 1865, although Dr. Beddoe began nearly ten years earlier to collect data from all over the continent. His untiring perseverance led him to take upward of one hundred thousand personal observations in twenty-five years. During our own civil war about a million recruits were examined in this respect, many of them being immigrants from all parts of Europe. The extent of the work which has been done since these first beginnings is indicated by the following approximate table:
It thus appears that the material is ample in amount. The great difficulty in its interpretation lies in the diversity of the systems which have been adopted by different observers. It is not easy to give an adequate conception of the confusion which
