winter, while in spring (February, March, and April) and in autumn (August, September and October) there are very marked falls to bad conduct, each individual tending to adhere to a conduct-curve of his own.  Wey does not himself appear to have noticed this seasonal periodicity.  Marro, however, has investigated this question in Turin on a large scale and reaches results not very dissimilar from those shown by Wey’s figures in New York.  He noted the months in which over 4,000 punishments were inflicted on prisoners for assaults, insults, threatening language, etc., and shows the annual curve in Tavola VI of his Caratteri dei Delinquenti.  There is a marked and isolated climax in May; a still more sudden rise leads to the chief maximum of punishment in August; and from the minimum in October there is rapid ascent during the two following months to a climax much inferior to that of May.

The seasonal periodicity of bad conduct in prisons is of interest as showing that we cannot account for psychic periodicity by invoking exclusively social causes.  This theory of psychic periodicity has been seriously put forward, but has been investigated and dismissed, so far as crime in Holland is concerned, by J.R.B. de Roos, in the Transactions of the sixth Congress of Criminal Anthropology, at Turin, in 1906 (Archivio di Psichiatria fasc. 3, 1906).

The general statistics of suicides in Continental Europe show a very regular and unbroken curve, attaining a maximum in June and a minimum in December, the curve rising steadily through the first six months, sinking steadily through the last six months, but always reaching a somewhat greater height in May than in July.[164] Morselli shows that in various European countries there is always a rise in spring and in autumn (October or November).[165] Morselli attributes these spring and autumn rises to the influence of the strain of the early heat and the early cold.[166] In England, also, if we take a very large number of statistics, for instance, the figures for London during the twenty years between 1865 and 1884, as given by Ogle (in a paper read before the Statistical Society in 1886), we find that, although the general curve has the same maximum and minimum points, it is interrupted by a break on each side of the maximum, and these two breaks occur precisely at about March and October.[167] This is shown in the curve in Chart 6, which presents the daily average for the different months.

The growth of children follows an annual rhythm.  Wahl, the director of an educational establishment for homeless girls in Denmark, who investigated this question, found that the increase of weight for all the ages investigated was constantly about 33 per cent. greater in the summer half-year than in the winter half-year.  It was noteworthy that even the children who had not reached school-age, and therefore could not be influenced by school-life, showed a similar,