If fertilization takes place, the fertilized egg buries itself in the wall and development of the embryo proceeds. Menstruation stops, the calcium salts being required for the growing embryo. There is likely to be no menstruation for a considerable time after delivery if the child is nursed, as is normal. This gives the uterus time for devolution to the normal, before a surplus of calcium salts sets the periodicity going again. If the egg which passes from the ovary to the uterus is not fertilized, it is excreted, the uterus goes through another monthly cycle of preparation for the period of intra-maternal environment, and so on indefinitely until the climacteric. This climacteric or decay of sexuality is a rather critical time, especially in women. It marks the period at which the metabolism can no longer support the strain of reproduction. A surplus of calcium brings on senility, as noted above. Withdrawal of the interests which centre in sex, together with the marked accompanying physical changes, involves a shift of mental attitude which is also frequently serious. A British coroner stated in the _British Medical Journal_ in 1900 (Vol. 2, p.792) that a majority of 200 cases of female suicide occurred at this period, while in the case of younger women suicide is peculiarly likely to occur during menstruation. Krugelstein and Lombroso, respectively, remark the same tendencies.[18] It is a matter of almost everyday observation that men and women in the neighbourhood of fifty suddenly find themselves disoriented in the world. Tolstoi, for example, who had written passionately of passion in his earlier years, suddenly awoke, according to his "Confessions," from what seemed to him afterward to have been a bad dream. In this case, the result was a new version of religion as a new anchorage for the man's life. It may be pacifism, prohibition, philanthropy, or any one of a very large number of different interests--but there must usually be something to furnish zest to a life which has ceased to be a sufficient excuse for itself. If freed from worry about economic realities, it is not infrequently possible for the first time for these people to "balance" their lives--to find in abstraction a rounded perfection for which earlier in life we seek in vain as strugglers in a world of change. Thus old people are often highly conservative, i.e., impatient of change in their social environment, involving re-orientation; they wish the rules of the game let alone, so they can pursue the new realities they have created for themselves. Socially, the old are of course a very important factor since a changed metabolism sets them somewhat outside the passionate interests which drive people forward, often in wrong directions, in the prime of life. Hence in a sense the old can judge calmly, as outsiders. Like youth before it has yet come in contact with complicated reality, they often see men and women as "each chasing his separate phantom."