The extinction of the families is undoubtedly due partly to other causes than the voluntary limitation of families—to a process of degeneration. A very remarkable proof of the degenerative character of the dying out of families is given by Pontus Fahlbeck in his book, "The Aristocracy of Sweden" (Fischer, Jena, 1903).
The six Figures C 38-43 give what is biologically of greatest interest in it. Note how the terribly quick extinction of the families of the nobility is inaugurated by catastrophic changes: rapid fall in the frequency of marriages, in the number of fertile marriages, and in the number of their progeny. The curves of the surviving families (red in the original tables) are for comparison. That we have to deal here with a natural and not a voluntary process is shown by the rapid increase in the mortality of male youth in the last generations; also by the extraordinary change in the proportion of the sexes of the children—which, of course, is beyond any control, marked preponderance of girls amongst the survivors (possibly also by the frequency of still-born male children).
A disturbance in the normal proportion of the sexes as a symptom of abnormal germ production may also assert itself in the opposite direction. O. Lorenz has pointed out the frequent occurrence of an extraordinary increase of male children immediately before the extinction of a family in the male line. One of the most celebrated of these cases is the one of the family of the Emperor Max II. He had six sons and two daughters, who all reached the age of maturity, but not a single male grandchild in the legitimate male line.
Fresh evidence is exhibited by von den Velden in Figure C 44. With the families described by von Riffel, who have died out in the male line, there is still a great preponderance of boys in the last generation in which boys have reached the age of sexual maturity, whereas there is a preponderance of females amongst the brothers and sisters of the wives of the last male issue of the family.
Families in Process of Extinction.
Figure C 44.