Of special interest is the wide prevalence of an attitude in coitus recalling that which prevails among quadrupeds. The frequency with which on the walls of Pompeii coitus is represented with the woman bending forward and her partner approaching her posteriorly has led to the belief that this attitude was formerly very common in Southern Italy. However that may be, it is certainly normal at the present day among various more or less primitive peoples in whom the vulva is often placed somewhat posteriorly. It is thus among the Soudanese, as also, in an altogether different part of the world, among the Eskimo Innuit and Koniags. The New Caledonians, according to Foley, cohabit in the quadrupedal manner, and so also the Papuans of New Guinea (Bongu), according to Vahness. The same custom is also found in Australia, where, however other postures are also adopted. In Europe the quadrupedal posture would seem to prevail among some of the South Slavs, notably the Dalmatians. (The different methods of coitus practiced by the South Slavs are described in Kryptadia vol. vi, pp. 220, et seq.) This method of coitus was recommended by Lucretius (lib. iv) and also advised by Paulus Æginetus as favorable to conception. (The opinions of various early physicians are quoted by Schurig, _Spermatologia_, 1720, pp. 232, et seq.). It seems to be a position that is not infrequently agreeable to women, a fact which may be brought into connection with the remarks of Adler already quoted (p. 131) concerning the comparative lack of adjustment of the feminine organs to the obverse position. It is noteworthy that in the days of witchcraft hysterical women constantly believed that they had had intercourse with the Devil in this manner. This circumstance, indeed, probably aided in the very marked disfavor in which coitus _a posteriori_ fell after the decay of classic influences. The mediæval physicians described it as _mos diabolicus_ and mistakenly supposed that it produced abortion (Hyrtl, op. cit., vol. ii, p. 87). The theologians, needless to say, were opposed to the _mos diabolicus_, and already in the Anglo-Saxon Penitential of Theodore, at the end of the seventh century, 40 days' penance is prescribed for this method of coitus. From the frequency with which they have been adopted by various peoples as national customs, most of the postures in coitus here referred to must be said to come within the normal range of variation. It is a mistake to regard them as vicious perversions.