in his mind to do any serious work, for he continually left off to go and give the other fellow an additional bit of a drubbing; so that at five o'clock I took pity on the dejected little fish, and removed him to another tank. (A description of the way in which the victorious male built a nest here follows. See vol. iii, p. 428.) He was by this time in glorious colour, bright red all over the gills and along the ventral region, light creamy pink or blue on the back, his eye a very sapphire for brightness and purity of blue. Yet would not his mates be coaxed to the nest. Dress as he might, and air his finery as he would, they remained obdurate, insensate, and unmoved. Then would he show his not unnatural pique and annoyance by running at them from a distance and giving them most ungallant digs in the ribs. This is, however, it should be stated in extenuation of his conduct, a recognized part of the mysteries of stickleback courtship. I therefore removed the females, placing them in a tank close by, so that the little gentleman could show off his attire in one tank, while the ladies gazed at him admiringly from the other, without danger of being pestered by his too urgent attentions. After a time one of the females put on her wedding finery, her sides becoming marked with bands of deeper brown; and as she seemed anxious to join the merry little monarch of the other tank, I transferred her thither. He at once became much excited, and looked, if possible, rosier and bluer-eyed than ever. He soon dashed off to the nest to see that all was there in readiness, and passed through it, remaining inside half a minute or so. After having thus prepared his nest for her reception he returned to the female, and swam slowly round and round her, frequently passing in front of her. The gay rogue! He knew that she could not resist those rosy cheeks and that bright blue eye. Nevertheless he found it his duty to dig her several times in the ribs, and was clearly somewhat annoyed that she delayed so long to come to his nest. Unfortunately I was then called away from my room, so that I did not on this occasion see her pass through the nest and lay her eggs there." For further particulars regarding the home-life of this and other kinds of stickleback, the reader is referred to the delightful book from which the above extract is taken.

THE LAW OF BEAUTY.-We have just seen that a male fish

may assume courtship colours of brilliant kind, but in some species the attractions are of a more elaborate nature. A good instance among British marine fishes is afforded by the Gemmeous Dragonet or Golden Skulpin (Callionymus lyra, fig. 1115), where the female is of a dull brown, and was formerly, under the name of the Sordid Dragonet, considered to be a distinct species. The male, however, is yellow, with spots and stripes of blue, besides which his first dorsal fin is relatively large, and

its first ray is drawn out into a long slender filament, which appears to be of the nature of an ornament. Holt has described the courtship of an allied species, the Spangled Dragonet (C. lineatus), and says regarding the male that—"its head and body are indescribable mingled harmony of many shades of brown and blue and green, set off with light-blue spots and pearlcoloured stripes; the anterior dorsal fin, which can be erected like a high sail, is golden yellow, studded with many white-edged blue ocelli; the tail fin is a blend of brown and yellow, set with turquoise spots; the belly fin is like dark-blue velvet sown with rows of turquoise; the pelvic fins are like golden-green satin,

fringed with dark blue, and spangled with small turquoise spots; and the pectoral fins are of a delicate lavender-gray, with serried dark-brown spots. The female is but a dish-clout in respect of him." In still another species of Dragonet (C. carebares), however, it is the female which is beautiful, and she no doubt takes the lead in courtship. It is interesting to note that Alcock has described an Indian flat-fish (Arnoglossus macrolophus) in which the male possesses a long crest, owing to the excessive development of the rays at the front end of the dorsal fin, somewhat as in the Dragonets above described.

COURTSHIP AND MATING OF INSECTS (INSECTA)

THE LAW OF BATTLE.-The jaws of some male beetles are of enormous size (fig. 1116), and to these are sometimes added conspicuous horn-like outgrowths from the head or thorax. These features have suggested such names as

stag beetle".

Fig. 1116.-A Tropical Beetle (Chiasognathus Grantii). Male on left; female on right

"rhinoceros beetle", &c. Such structures may possibly be used in fights for the possession of mates, but this has not so far been proved, and the matter must remain unsettled until our knowledge of habits is more complete.

Various male insects have, however, been observed fighting for partners, and Darwin (in The Descent of Man) gives appa

rently well-authenticated instances of this among digging wasplike forms (Cerceris), Saw-Flies, Bees, and even Butterflies.

THE LAW OF BEAUTY.-Male insects, especially Butterflies, are often more beautiful and more conspicuous than individuals of the other sex, but it is necessary here to be cautious in drawing conclusions, for courtship is not the only business of life. That the female should often be in plain attire would often appear to be a protective measure, as it is more important for the welfare of the species that she should escape from enemies than her comparatively useless partner. The same explanation may be given where female butterflies are conspicuous as the result of protective mimicry (see vol. ii, p. 311). This line of argument, however, may easily be carried too far, and the usually brighter colours of the male in insects (and other animals) cannot be satisfactorily explained simply as one of the results of greater energy and activity. In many groups the eyes are complex and highly developed, and that they often minister to a "colour-sense" is generally admitted, the relations between insects and flowers, for example, affording much evidence in this direction (see p. 85). Admitting this, Wallace suggests that his theory of recognition marks (see pp. 132, 140) may account for many of the distinctive colours and markings of insects. In arguing against this view Poulton says (in The Colours of Animals)" that the beauty of the colours and patterns displayed in courtship can never be explained by this principle. For the purposes of recognition, beauty is entirely superfluous and indeed undesirable; strongly-marked and conspicuous differences are alone necessary. But these, which are so well marked in Warning Colours, are not by any means characteristic of those displayed in courtship. If an artist, entirely ignorant of natural history, were asked to arrange all the brightly-coloured butterflies and moths in England in two divisions, the one containing all the beautiful patterns and combinations of colour, the other including the staring, strongly-contrasted colours, and crude patterns, we should find that the latter would contain, with hardly an exception, the species in which independent evidence has shown, or is likely to show, the existence of some unpleasant quality. The former division would contain the colours displayed in courtship and when the insect is on the alert, concealed at other times. The immense difference between the two divisions, the one most pleasing, the other highly repug

nant to our æsthetic susceptibilities, seems to me to be entirely unexplained if we assume that the colours of both are intended. for the purposes of recognition. But these great differences are to be expected if we accept Mr. Darwin's views; for the colours and patterns of the latter division appeal to a vertebrate enemy's sense of what is conspicuous, while those of the former appeal to an insect's sense of what is beautiful. It is, of course, highly remarkable that our own æsthetic sense should so closely correspond with that of an insect. I believe, however, that it is possible to account for this wonderful unanimity in taste. Our

Fig. 1117.-Orange-Tips (Anthocharis cardamines) in Centre (male left; female right). Cabbage-Whites (Pieris brassica) at Sides (male right; female left)

standards of beauty are largely derived from the contemplation of the numerous examples around us, which, strange as it may seem, have been created by the æsthetic preferences of the insect world."

Among our native species the Orange-Tip Butterfly (Anthocharis cardamines, fig. 1117) may probably be taken as a good example of courtship coloration. As in most other butterflies, these insects bring their wings together when they settle, and are then inconspicuous, as the under surfaces of these organs are protectively coloured, being white with greenish mottlings. This is more particularly true for the female Orange-Tip, which is often found sleeping among the blossoms of Wild Chervil (Anthriscus sylvestris), with the colour-scheme of which it harmonizes wonder

VOL. IV.

105