Page:Popular Science Monthly Volume 62.djvu/247

Rh sexual character is too obvious to need definition. As a matter of fact there is considerable difference of opinion. Since Hunter first spoke of the 'secondary properties' of sex, which he regarded as dependent on the primary, only developing at puberty, and principally, though not entirely, confined to the male, the conception has very much changed; there has been a tendency to throw all sorts of miscellaneous sexual differences into the category. I have suggested that it would be convenient to introduce a group of 'tertiary' sexual characters, keeping the term 'secondary' to its original sense and reserving as 'tertiary' all those minor differences which are not obvious, which can have no direct influence on mating, and only exist as averages; such are the composition of the blood and the shape of the bones.

It is difficult to correct all the errors and confusions which Professor Pearson falls into at this point. He remarks that we must not regard the greater prevalence of idiocy among men as evidence of greater male variability, unless we count on the other side the greater prevalence of insanity among women. The error here is double. As a matter of fact, although in England and Wales during recent years the incidence of insanity has been as great on women as on men, nearly everywhere else it is markedly greater in the case of men. Indeed even in England and Wales, at the present time, if we may trust the Commissioners in Lunacy in their latest annual report (1902), the incidence of insanity as indicated by the admissions to asylums, is, in ratio to the male population, still slightly greater in the case of men. Professor Pearson has been misled by the greater accumulation of females in asylums, failing to take into consideration the greater longevity of women, which among the insane is specially marked. But even if the facts had been as stated by