Courtship eyes

to normal lateral eyes like those of the females. The reduction of pigment and the presence of a thick layer of homogeneous fluid. . . has led to the conclusion that the special function of these eyes is to discern moving objects in the dusk, to enable the male to secure a mate in the airy twilight dance of the short-lived Mayflies " (fig. 1120).

In many of the nocturnal Beetles which are known as Glow Worms the female is wing

Eye

Br

Eye

Fig. 1120.-Horizontal Sections through the Heads of a Male (right) and Female (left) Mayfly (Cloe fuscata), enlarged. Br., Brain; V.G., ventral ganglion; G., Gullet; M., mouth-parts.

less and grub-like, as in our familiar native species (Lampyris noctiluca), and practically monopolizes the power of emitting a clear light from peculiar patches of skin along the sides of the body. As the eyes of the male in such cases are well developed, sometimes remarkably so, the object of the arrangement is tolerably clear. In some of the insects of this sort, native to South America, the difference in appearance between the male and female is particularly marked, the latter sex closely resembling the larva (fig. 1121). In Paraguay some of these grub-like females are known as "railway-beetles", being said to exhibit a "danger signal" at either end, and a row of "caution signals" along each side, or, to speak less metaphorically, possessing luminous organs in the positions (Phengodes Hieronymi), 3. Male on left; indicated which respectively emit red and green light. A cynical remark might here be made, as to the appropriateness of such colours in the female sex.

There is still, however, much to be learnt as to the meaning of luminous organs in insects, for it appears that in species belonging to the same family as the Glow-Worms, e.g. the well-known FireFlies (Luciola) of South Europe, the light-giving power is more

strongly developed in the males. Nor can it well be deemed as probable that they are here the sought and not the seekers, for we should then expect to find the eyes of the female better developed than those of the opposite sex, but this is not the case.

COURTSHIP AND MATING OF SPIDERS (ARANEIDA)

The lot of a male spider is not altogether desirable, for he is much smaller than his prospective partner, who sometimes makes a meal of him. It is scarcely worth while in this case to make separate headings of the Laws of Battle and Beauty, for both may find their application at the same time. Dr. and Mrs. Peckham have investigated this subject as regards species of the family of Hunting Spiders (Attida). Their observations, some of which are quoted below (from Papers of the Natural History Society of Wisconsin, 1889), are intensely interesting, and clearly prove that the females of various species do not mate at random with any swain that offers, often being exceedingly fastidious, and sometimes tragically cruel. The males generally possess special markings and ornaments, which they display in ways that often appear grotesque; they also perform complex evolutions, some of these being rather weird "dances" (fig. 1122), of which one (for Saitis pulex) is thus described:-" He saw her as she stood perfectly still, 12 inches away; the glance seemed to excite him, and he moved toward her; when some 4 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 pair of legs up and under, leans so far over as to be in danger of losing his balance, which he only maintained by sidling rapidly towards the lowered side. The palpus, too, on this side was turned back to correspond to the direction of the legs nearest it (see fig. 1122). He moved in a semicircle for about 2 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 towards him, while he, raising his first pair of legs, extends them upward and forward to hold her off, but withal slowly retreats.

Again and again he circles from side to side, she gazing towards him in a softer mood, evidently admiring the grace of his antics. This is repeated until we have counted 111 circles made by the ardent little male. Now he approaches nearer and nearer, and when almost within reach, whirls madly around and around her, she joining and whirling with him in a giddy maze." One feels quite glad to hear that the suit of this particular male was successful. He was decidedly in luck, for we learn that the females

Fig. 1122.-Courtship Attitudes of Male Spiders, enlarged. A, Saitis pulex, dancing. B, Habrocestum splendens approaching female. C and D, Red and black varieties of Astia vittata in approaching attitudes.

of his species are very fastidious, and frequently turn admirers

away.

A number of males often compete for the good graces of a single female in some of the species observed, in which case the latter takes some time to make up her mind. Competing wooers from time to time interrupt their antics to tussle with one another. Boldness or persistence sometimes wins the day. The male of one species (Dendryphantes capitatus) may frisk around for hours displaying his special beauties, until "at last the female, either won by his beauty or worn out by his persistence, accepts his addresses". And in another form (Hasarius Hoyi) a male was brave enough to walk up to an evidently displeased female, "when she seized him and seemed to hold him by the head for

a minute, he struggling. At last he freed himself and ran away.' Only to come back again, however, for we read that: "This same male after a time courted her successfully". Tragic courtships were also observed, as in the case of a particularly ruthless female (of Phidippus morsitans) who behaved thus:-"The two males that we provided for her had offered her only the merest civilities, when she leaped upon them and killed them".

In one remarkable species (Astia vittata) the female is red, and there are two kinds of male, red and black respectively, which court in different ways (fig. 1122). When they are rivals, black is invariably the winning colour.

It has been suggested that the small size and great activity of male spiders are adaptations which to some extent reduce the appalling dangers of courtship. In leaving this group the writer ventures to express a hope that many field naturalists may feel moved to observe the habits of common native forms on the lines so successfully followed by Dr. and Mrs. Peckham, in this and other fields (see p. 55). Anything approaching the skill and devotion of these investigators, applied to the study of almost any species, would most assuredly yield a rich harvest of valuable results.

COURTSHIP AND MATING OF CRUSTACEANS
(CRUSTACEA)

Comparatively little is known about the love affairs of the higher members of this group, which deserves far more attention

in this matter than has so far been bestowed upon it. It will perhaps suffice here to quote an exceedingly interesting account which is given by Alcock (in A Naturalist in Indian Seas) of a little Fiddler Crab (Gelasimus annulipes, fig. 1123), which is very abundant on the mud-flats at the mouths of the Godávari and Kistna. The pincers of the female are small, and only used in feeding, but in the male one of them is of great size and bright pink in colour, serving as an ornament and also as a weapon. Alcock thus describes the courtship of these little

Fig. 1123.-Indian Fiddler Crab (Gelasimus annulipes).
Female on left; male on right

animals:--“ Landing one afternoon in March upon a cheerful mudflat of the Godávari sea-face, I was bewildered by the sight of a multitude of small pink objects twinkling in the sun, and always, like will-of-the-wisps, disappearing as I came near to them, but flashing brightly on ahead as far as the eye could reach. It was not until I stayed perfectly quiet that I discovered that these twinkling gems were the brandished nippers of a host of males of Gelasimus annulipes. By long watching I found out that the little creatures were waving their nippers with a purpose-the purpose apparently being to attract the attention of an occasional infrequent female, who, uncertain, coy, and hard to please, might be seen unconsciously sifting the sand at the mouth of her burrow. If this demure little flirt happened to creep near the burrow of one of the males, then that favoured individual became frantic with excitement, dancing round his domain on tiptoe and waving his great cherry hand as if demented. Then, if another male, burning with jealousy, showed a desire to interfere, the two puny little suitors would make savage back-handed swipes at one another, wielding their cumbrous hands as if they had no weight at all.

Some of the Crustaceans possess the power of emitting sounds (see p. 37), possibly to serve as love-calls, and the courtship habits of such species would probably prove interesting.