It is a fact, however, that Asia was the chief area of evolution and differentiation of man and that the various groups had their main development there and not on the peninsula we call Europe. Many of the races of Europe, both living and extinct, did come from the East through Asia Minor or by way of the African littoral, but most of the direct ancestors of existing populations have inhabited Europe for many thousands of years. During that time numerous races of men have passed over the scene. Some undoubtedly have utterly vanished and some have left their blood behind them in the Europeans of to-day. We now know, since the elaboration of the Mendelian Laws of Inheritance, that certain bodily characters, such as skull shape, stature, eye color, hair color and nose form, some of which are so-called unit characters, are transmitted in accordance with fixed laws, and, further, that various characters which are normally correlated or linked together in pure races may, after a prolonged admixture of races, pass down separately and form what is known as disharmonic combinations. Such disharmonic combinations are, for example, a tall brunet or a short blond; blue eyes associated with brunet hair or brown eyes with blond hair. The process of intermixture of characters has gone far in existing populations and through the ease of modern methods of transportation this process is going much further in Europe and in America. The results of such mixture are not blends or intermediate types, but rather mosaics of contrasted characters. Such blends, if any, as ultimately occur are too remote to concern us here. The crossing of an individual of pure brunet race with an individual of pure blond race produces in the first generation offspring which are distinctly dark. In subsequent generations, brunets and blonds appear in various proportions but the former tend to be much the more numerous. The blond is consequently said to be recessive to the brunet because it recedes from view in the first generation. This or any similar recessive or suppressed trait is not lost to the germ plasm, but reappears in later generations of the hybridized stock. A similar rule prevails with other physical characters. In defining race in Europe it is necessary not only to consider pure groups or pure types but also the distribution of characters belonging to each particular subspecies of man found there. The interbreeding of these populations has progressed to such an extent that in many cases such an analysis of physical characters is necessary to reconstruct the elements which have entered into their ethnic composition. To rely on averages alone leads to misunderstanding and to disregard of the relative proportion of pure, as contrasted with mixed types.