Next above these is another well-defined stratum,--the self-supporting, but unskilled and illiterate. Then all who fall between _PQ_ and _RS_ are characterized by mediocrity, and they constitute "the masses." In all new countries, and as it would seem at the present time also in central Europe, there is a very strong current upwards from the lower to the upper strata of _PQRS_. Universal education tends to produce such a current. Talented men of the period are very often born in humble circumstances, but succeed in taking their true place in the societal scale. It is true, of course, that there is a counter-current of degenerate sons and grandsons. The present diagram is made unsymmetrical with respect to _MN_ to express the opinion that the upper strata of _PQRS_ (the lower professional and the semiprofessional classes) are now, in any civilized society, larger in proportion than symmetry would indicate.[68] The line _MN_ is therefore a mode, and the class upon it is the modal class of the society, by means of which one society might be compared with another. +50.+ Galton estimated the number of men of genius in all history at four hundred. An important fraction of these were related by blood. The "men of the time" he rates at four hundred and fifty in a million, and the more distinguished of them at two hundred and fifty in a million. These latter he defines by saying that a man, to be included amongst them, "should have distinguished himself pretty frequently, either by purely original work, or as a leader of opinion." He finds that illustrious men are only one in a million. On the other hand, idiots and imbeciles in England and Wales are one in four hundred, of whom thirty per cent can be educated so as to be equal to one third of a normal man each; forty per cent can be made worth two thirds of a man; twenty-five or thirty per cent pass muster in a crowd. Above these are silly persons whose relatives shield them from public knowledge. Then above these come the Dundreary type.[69]