purposes, but simply to brace the stem.  The dart is contained in a dart-sac, which is attached as a sort of pocket to the vagina, at no great distance from its orifice.  In Helix aspersa the dart is about five-sixteenths of an inch in length, and one-eighth of an inch in breadth at its base.  It appears most probable that the dart is employed as an adjunct for the sexual act.  Besides the fact of the position of the dart-sac anatomically, we find that the darts are extended and become imbedded in the flesh, just before or during the act of copulation.  It may be regarded, then, as an organ whose functions induce excitement preparatory to sexual union.  It only occurs in well-grown specimens. (Rev. L.H.  Cooke, “Molluscs,” Cambridge Natural History, vol. iii, p. 143.)

Racovitza has shown that in the octopus (Octopus vulgaris) courtship is carried on with considerable delicacy, and not brutally, as had previously been supposed.  The male gently stretches out his third arm on the right and caresses the female with its extremity, eventually passing it into the chamber formed by the mantle.  The female contracts spasmodically, but does not attempt to move.  They remain thus about an hour or more, and during this time the male shifts the arm from one oviduct to the other.  Finally he withdraws his arm, caresses her with it for a few moments, and then replaces it with his other arm. (E.G.  Racovitza, in Archives de Zooelogie Experimentale, quoted in Natural Science, November, 1894.)

The phenomena of courtship are very well illustrated by spiders.  Peckham, who has carefully studied them, tells us of Saitis pulex:  “On May 24th we found a mature female, and placed her in one of the larger boxes, and the next day we put a male in with her.  He saw her as she stood perfectly still, twelve inches away; the glance seemed to excite him, and he at once moved toward her; when some four inches from her he stood still, and then began the most remarkable performances that an amorous male could offer to an admiring female.  She eyed him eagerly, changing her position from time to time so that he might be always in view.  He, raising his whole body on one side by straightening out the legs, and lowering it on the other by folding the first two pairs of legs up and under, leaned so far over as to be in danger of losing his balance, which he only maintained by sliding rapidly toward the lowered side.  The palpus, too, on this side was turned back to correspond to the direction of the legs nearest it.  He moved in a semicircle for about two inches, and then instantly reversed the position of the legs and circled in the opposite direction, gradually approaching nearer and nearer to the female.  Now she dashes toward him, while he, raising his first pair of legs, extends them upward and forward as if to hold her off, but withal slowly retreats.  Again and again he circles from side to side, she gazing toward him