arately) about
the month of July. (In the second period, however, which contains
the smallest number of births, the minimum occurs in September.)
From that low minimum there is steady and unbroken rise up to the
chief maximum in November. (In the first period, however, the
maximum is delayed till January, and in the second period it is
somewhat diffused.) There is a tendency to a minor maximum in
February, specially well marked in the third and most important
period, and in the first period delayed until March.

A very curious and perhaps not accidental coincidence might be briefly
pointed out before we leave this part of the subject. It is found[157] by
taking 3000 cases of children dying under one year that, among the general
population, children born in February and September (and therefore
conceived in May and December) appear to possess the greatest vitality,
and those born in June, and, therefore, conceived in September, the least
vitality.[158] As we have seen, May and December are precisely the periods
when conceptions in Europe generally are at a maximum, and September is
precisely the period when they are at a minimum, so that, if this
coincidence is not accidental, the strongest children are conceived when
there is the strongest tendency to procreate, and the feeblest children
when that tendency is feeblest.

Nelson, in his study of dreams and their relation to seasonal ecbolic
manifestations, does not present any yearly ecbolic curve, as the two
years and a half over which his observations extend scarcely supply a
sufficient basis. On examining his figures, however, I find there is a
certain amount of evidence of a yearly rhythm. There are spring and autumn
climaxes throughout (in February and in November); there is no December
rise. During one year there is a marked minimum from May to September,
though it is but slightly traceable in the succeeding year. These figures
are too uncertain to prove anything, but, as far as they go, they are in
fair agreement with the much more extensive record, that of W.K. (_ante_
p. 113), which I have already made use of in discussing the question of a
monthly rhythm. This record, covering nearly twelve years, shows a general
tendency, when the year is divided into four periods (November-January,
February-April, May-July, August-October) and the results summated, to
rise steadily throughout, from the minimum in the winter period to the
maximu