(M146) Thus it would seem that a custom of putting to death all firstborn children has prevailed in many parts of the world. What was the motive which led people to practise a custom which to us seems at once so cruel and so foolish? It cannot have been the purely prudential consideration of adjusting the numbers of the tribe to the amount of the food-supply; for, in the first place, savages do not take such thought for the morrow,(507) and, in the second place, if they did, they would be likely to kill the later born children rather than the firstborn. The foregoing evidence suggests that the custom may have been practised by different peoples from different motives. With the Semites, the Italians, and their near kinsmen the Irish the sacrifice or at least the consecration of the firstborn seems to have been viewed as a tribute paid to the gods, who were thus content to receive a part though they might justly have claimed the whole. In some cases the death of the child appears to be definitely regarded as a substitute for the death of the father, who obtains a new lease of life by the sacrifice of his offspring. This comes out clearly in the tradition of Aun, King of Sweden, who sacrificed one of his sons every nine years to Odin in order to prolong his own life.(508) And in Peru also the son died that the father might live.(509) But in some cases it would seem that the child has been killed, not so much as a substitute for the father, as because it is supposed to endanger his life by absorbing his spiritual essence or vital energy. In fact, a belief in the transmigration or rebirth of souls has operated to produce a regular custom of infanticide, especially infanticide of the firstborn. At Whydah, on the Slave coast of West Africa, where the doctrine of reincarnation is firmly held, it has happened that a child has been put to death because the fetish doctors declared it to be the king’s father come to life again. The king naturally could not submit to be pushed from the throne by his predecessor in this fashion; so he compelled his supposed parent to return to the world of the dead from which he had very inopportunely effected his escape.(510) The Hindoos are of opinion that a man is literally reborn in the person of his son. Thus in the _Laws of Manu_ we read that “the husband, after conception by his wife, becomes an embryo and is born again of her; for that is the wifehood of a wife, that he is born again by her.”(511) Hence after the birth of a son the father is clearly in a very delicate position. Since he is his own son, can he himself, apart from his son, be said to exist? Does he not rather die in his own person as soon as he comes to life in the person of his son? This appears to be the opinion of the subtle Hindoo, for in some sections of the Khatris, a mercantile caste of the Punjaub, funeral rites are actually performed for the father in the fifth month of his wife’s pregnancy. But apparently he is allowed, by a