and ethereal as the butterflies, a whole armory of keen weapons for use in coitus.  These were described in detail in an elaborate and fully illustrated memoir by P.H.  Gosse ("On the Clasping Organs Ancillary to Generation in Certain Groups of the Lepidoptera,” Transactions of the Linnaean Society, second series, vol. ii, Zooelogy, 1882).  These organs, which Gosse terms harpes (or grappling irons), are found in the Papilionidae and are very beautiful and varied, taking the forms of projecting claws, hooks, pikes, swords, knobs, and strange combinations of these, commonly brought to a keen edge and then cut into sharp teeth.

    It is probable that all these structures serve to excite the
    sexual apparatus of the female and to promote tumescence.

To the careless observer there may seem to be something vicious or perverted in such manifestations in man.  That opinion becomes very doubtful when we consider how these tendencies occur in people living under natural conditions in widely separated parts of the world.  It becomes still further untenable if we are justified in believing that the ancestors of men possessed projecting epithelial appendages attached to the penis, and if we accept the discovery by Friedenthal of the rudiment of these appendages on the penis of the human fetus at an early stage (Friedenthal, “Sonderformen der menschlichen Leibesbildung,” Sexual-Probleme, Feb., 1912, p. 129).  In this case human ingenuity would merely be seeking to supply an organ which nature has ceased to furnish, although it is still in some cases needed, especially among peoples whose aptitude for erethism has remained at, or fallen to, a subhuman level.

At first sight the connection between love and pain—­the tendency of men to delight in inflicting it and women in suffering it—­seems strange and inexplicable.  It seems amazing that a tender and even independent woman should maintain a passionate attachment to a man who subjects her to physical and moral insults, and that a strong man, often intelligent, reasonable, and even kind-hearted, should desire to subject to such insults a woman whom he loves passionately and who has given him every final proof of her own passion.  In understanding such cases we have to remember that it is only within limits that a woman really enjoys the pain, discomfort, or subjection to which she submits.  A little pain which the man knows he can himself soothe, a little pain which the woman gladly accepts as the sign and forerunner of pleasure—­this degree of pain comes within the normal limits of love and is rooted, as we have seen, in the experience of the race.  But when it is carried beyond these limits, though it may still be tolerated because of the support it receives from its biological basis, it is no longer enjoyed.  The natural note has been too violently struck, and the rhythm of love has ceased to be perfect.  A woman may desire to be forced, to be roughly forced,