[Sidenote: But the uncertainty as to the paternity of the Roman kings may only mean that in later times the names of their fathers were forgotten.] The hypothesis that the Latin kings may have been begotten at an annual festival of love is necessarily a mere conjecture, though the traditional birth of Numa on the festival of the Parilia, when shepherds leaped across the spring bonfires,[887] as lovers leap across the Midsummer fires, may perhaps be thought to lend it a faint colour of probability. But it is quite possible that the uncertainty as to their fathers may not have arisen till long after the death of the kings, when their figures began to melt away into the cloudland of fable, assuming fantastic shapes and gorgeous colouring as they passed from earth to heaven. If they were alien immigrants, strangers and pilgrims in the land they ruled over, it would be natural enough that the people should forget their lineage, and forgetting it should provide them with another, which made up in lustre what it lacked in truth. The final apotheosis, which represented the kings as not merely sprung from gods but as themselves deities incarnate, would be much facilitated if in their lifetime, as we have seen reason to think, they had actually laid claim to divinity. [Sidenote: Where descent is traced through women only, girls of the highest rank may be married to men of humble birth, even to aliens and slaves.] If among the Latins the women of royal blood always stayed at home and received as their consorts men of another stock, and often of another country, who reigned as kings in virtue of their marriage with a native princess, we can understand not only why foreigners wore the crown at Rome, but also why foreign names occur in the list of the Alban kings. In a state of society where nobility is reckoned only through women—in other words, where descent through the mother is everything, and descent through the father is nothing—no objection will be felt to uniting girls of the highest rank to men of humble birth, even to aliens or slaves, provided that in themselves the men appear to be suitable mates. What really matters is that the royal stock, on which the prosperity and even the existence of the people is supposed to depend, should be perpetuated in a vigorous and efficient form, and for this purpose it is necessary that the women of the royal family should bear children to men who are physically and mentally fit, according to the standard of early society, to discharge the important duty of procreation. Thus the personal qualities of the kings at this stage of social evolution are deemed of vital importance. If they, like their consorts, are of royal and divine descent, so much the better; but it is not essential that they should be so.