Popular Science Monthly/Volume 31/October 1887/The Theory of Tittlebats
|THE THEORY OF TITTLEBATS.|
THE last theory of tittlebats of which I remember to have heard anything was that broached by Mr. Pickwick in connection with his profound and celebrated researches into the origin of the Hampstead Ponds. The suggestion of a causal connection between organism and environment, thus implied by the very title of Mr. Pickwick's paper, might lead one to suppose that the philosopher of the Fleet may have been really an early evolutionist, a Darwinian before Darwin, and an unconscious precursor of the now fashionable biologists, who account for everything on the Topsy principle of supposing that it "growed so." For undoubtedly the tittlebat was developed in, for, and by his native ponds, and any comprehensive theory of his existence and history must necessarily begin with the environment that produced him. Unfortunately, however, nothing now remains of Mr. Pickwick's valuable disquisition, except the bare title, enshrined among the posthumous papers of the club that bore his name; and I am therefore compelled, in reconstructing the theory of tittlebats on my own account, entirely to ignore the labors of my distinguished predecessor, and begin again de novo from the very outset.
The name itself of the tittlebat, I regret to say, appears in Mr. Pickwick's lost memoir in so debased and corrupt a form as scarcely to be recognizable to the philological student. His true title, I need hardly remark in this age of inquiry, ought to be stickleback; and he is so called in virtue of the stickles, spines, thorns, or prickles which represent and replace the first dorsal fin in all his kindred. But though the stickleback is so small a fish as even to have excited the scorn and ridicule of our great novelist, he can boast of almost as many aliases as the French counts and other sporting gentlemen who periodically return to journalistic fame under the ever-green beading of "The Great Turf Frauds." Besides his recognized literary English name of Stickleback, with its vulgar London variant Tittlebat, he is also diversely known to the ingenuous youth of this kingdom as the Banestickle, the Jack Bannel, the Harry Banning, the Sharpling, the Ban tide, the Tanticle, the Hackle, the Sharpnails, the Stanstickle, the Tommy Parsy, the Prickleback, the Barmy, and the Tinker; all names implying at once a certain amount of affectionate regard on the part of his sponsors not uncombined with a due respect (the child of experience) for his remarkable offensive and defensive powers. A true theory of tittlebats would have to account not only for the peculiarities of bony structure which have secured the stickleback these his many names, but also for the oddities of domestic arrangement which I shall further unfold in the course of this article.
The common English stickleback, with whom I propose here chiefly to deal, is a fresh-water fish, much discovered in ponds and small rivers, and abundant everywhere in the neighborhood of London. Many famous anglers, as Frank Buckland used to observe, were first "entered" for the noble sport by fishing for stickleback in the Regent's Canal. The fishing is most frequently pursued in the following fashion: You take a stick with a piece of thread tied to it, and a short bit of worm fastened to the string by the middle without any hook or even a bent pin to represent one. When the stickleback, who is naturally a greedy feeder, approaches the worm, he quickly swallows it, and you pull him up with a jerk before he has had time effectually to disgorge his gulped-down mouthful. Expert anglers at this particular task have even been known to jerk up two sticklebacks at a time, each intent upon one end of the worm; but this is a fine point of science not to be imitated by the uninstructed tyro. The fish, when landed, are consigned to pickle-bottles filled with water, and are commonly sold to the proprietors of domestic aquariums for the small charge of a penny a dozen. In this way, a working acquaintance with the habits Two-Spined Stickleback (Gasterosteus biaculeatus.) and manners and peculiarities of the stickleback has been generally diffused throughout a large portion of the unscientific British population.
Nevertheless, I hold it is afatal error to suppose that the theory of tittlebats falls in any way below the dignity of a profound philosopher. On the contrary, there are points in the psychology and physiology of the common stickleback which merit the close and undivided attention of the most accomplished naturalist.
I will begin with one of the best-known habits of the stickleback, its nest-building instinct; because that is really the one of its peculiarities which most affects the theory of tittlebats, and has the deepest interest and the widest implications for the general reader.
If you put a pair of assorted sticklebacks into a small aquarium, and supply them well with food during the early spring, you will find that after a short time the male fish begins to undergo a remarkable change of personal appearance. His coloration grows brighter and more beautiful; his throat and belly assume a deep crimson hue; his eyes acquire a brilliant bluish-green metallic luster, like the gorget of a humming-bird; and in the well-chosen words of his panegyrist, Mr. Warington, his whole body becomes almost translucent, and seems to glow as with some mysterious internal brightness. It is the season of courtship, and the stickleback is adorning himself in his courting suit.
"In the spring a ruddier crimson comes upon the robin's breast,
In the spring the wanton lapwing gets himself another crest,
In the spring a livelier iris changes on the burnished dove,
In the spring a young man's fancy lightly turns to thoughts of love."
The name of the stickleback falls unfortunately below the level of the lyrical muse, or else he might perhaps form a fifth member in that lovers' quartet. For no creature decks himself out in more gorgeous nuptial colors, or arrays himself more like Solomon in all his glory against his wedding-day, than the common little Hampstead tittlebat of Mr. Pickwick's missing dissertation.
Theoretically, of course (and we are all on the theory of tittlebats here), this assumption by the stickleback of special colors and ornaments for the pairing-season is all of a piece with the numerous other devices of Nature for securing the due selection by animals of the handsomest, strongest, and most vigorous mates. Many of the more brilliant animals don their finest decorations for the period of courtship only. The crests and lappets of the herons and egrets are developed and retained during the summer alone; they fall off as soon as winter arrives. The African widow-birds deck themselves out in the nesting-season with very long and conspicuous plumes, which disappear again, and leave them as mere inconspicuous little brown birds, after the brood is reared. The crested newt puts on his vandyked head-gear, and dapples his body with orange and crimson spots, at the approach of spring-tide. The speckled trout becomes livelier in hue; the salmon shine with brighter silver; the lizards acquire their metallic throat-pouches. It is at such times alone that the face of the mandrill glows with blue and purple, or that the rhesus monkey blushes a vivid crimson. Throughout the whole of nature, in fact, all the most beautiful animals attain their highest beauty in the season of courtship, and many which are never beautiful at other times then put on the most decorative ornaments or the most gorgeous coloring. This is true alike of the wings of butterflies, and of the song of crickets; it is true of the gemmeous dragonet and of the butterfly gurnard, of the peacock and the humming-bird, of the bird-of-paradise and the argus pheasant, of the perfume of the musk-deer and the antlers of the stag, of the lion's mane and the monkeys' beards, crests, and gorgets. All alike are assumed for the self-same purpose, and all are useful merely to charm the fickle senses of the proverbially coyer and more uncertain sex.
The stickleback has acquired his gorgeous wedding-garb, in accordance with a general law of animal life, in order to please and attract to himself the attention of his aesthetic and fastidious mates. "After the breeding-season," says Mr. Darwin, "these colors all change, the throat and belly become of a paler red, the back more green, and the glowing tints subside." Moreover, as usually happens in the case of all highly decorated animals, your stickleback further resembles Solomon in being a most undisguised polygamist in the natural state; and his brilliant hues have, no doubt, been developed to charm and draw to his side as many as possible of the female fish. Polygamous animals, in other words, are always handsome, because only the handsomest succeed in attracting to themselves a harem, and so handing on their peculiarities to future generations. Furthermore, the sticklebacks are all great fighters; and it may be broadly laid down once more as a general principle of animal life, and at the same time a contribution to the theory of tittlebats, that all very handsome and decorated creatures are naturally pugnacious of disposition. Thus stags fight one another with their branching antlers for the possession of the does. Salmon constantly join battle and tear one another to pieces savagely on the recognized spawning-beds. The polygamous ruff, distinguished from his sober-suited mate the reeve by his curious crest, and by the great collar of plumes from which his name is taken, is as full of the Homeric joy of battle as a game-cock, and quite as gamy. The wild Sumatran ancestor of our own barn-door fowl "does battle in defense of his seraglio till one of the combatants drops down dead." Blackcock and capercailzie assemble annually at regular tournaments, to fight one another, and display their beauty before their expectant and undecided dames; and on such occasions Kovalevsky has seen the snow of their arenas in Russia all red with blood, and covered with the torn-out feathers of the champions. Most of the handsomest birds and animals, indeed, are provided with special weapons for these fierce encounters, such as the spurs of game-birds, the horns of antelopes, the antlers of stags, the tusks of the musk-deer, the wing-darts of the palamedia, and the fierce spiny fins of the most decorative fishes. Even the dainty little humming-birds themselves are prodigious fighters, and I have seen them engaging; one another in their aërial battles with the utmost pluck, vigor, and endurance. Furthermore, beauty in animals is almost always accompanied, as Dr. Günther has observed, by a very hasty and irritable temper.
And now, I think, we are beginning to get a little nearer toward the theory of tittlebats. For the male stickleback is a prodigious warrior, and, when he meets a rival of his own kind, he engages with him at once in deadly warfare. Their battles, says Mr. Darwin, are at times desperate, for these puny combatants fasten tight on each other for several seconds, tumbling over and over again, until their strength appears utterly exhausted. Bold and pugnacious as they are, however, it is only my lords who thus fiercely contend with one another; their demure little mates remain always perfectly pacific, gentle, and even-tempered. With the rough-tailed stickleback, the males while fighting swim round and round one another, biting and endeavoring to pierce each other's mailed skin with their raised lateral spines or lances. Small as they are, their bite is very severe, and inflicts a deadly wound upon their antagonist; and Mr. Noel Humphreys remarks that they use their lateral spines with fierce effect, so that he has seen one brave stickleback during a stout battle rip up his opponent from end to end, till the vanquished hero sank to the bottom and died ingloriously.
It is during the moment of battle, and just before and after it, that the colors of all fighting animals become invariably most intense. The reason is plain: battle is joined during the mating-season, and "before the face of maidens and of dames"; and, as in human tournaments, the ladies stand by to applaud the conquerors and to reward their prowess. They are themselves the prize of the encounter they stimulate. Besides, the highest physical vigor and the highest excitement bring out the greatest beauty both of men and animals. The angrier you make a mandrill, the more vividly tinted are his cheeks and callosities. The frilled lizards and flying-dragons glow with all the brightest colors of the rainbow when you tease or annoy them. The turkey-cock swells his crimson wattles and spreads his ruffled feathers to the utmost at sight of a rival or a mischievous boy. There is a little hot-tempered fish known as Betta pugnax, and kept as a sort of domestic pet by the Siamese (much as the Christian English gentleman of forty or fifty years since kept fighting-cocks) to display its prowess for the edification of the Mongolian intelligence. "When in a state of quiet," says Cantor, "its dull colors present nothing remarkable; but if two be brought together, or if one sees its own image in a looking-glass, the little creature becomes suddenly excited, the raised fins and the whole body shine with metallic colors of dazzling beauty, while the projected gill-membrane, waving like a black frill round the throat, adds something of grotesqueness to the general appearance. In this state, it makes repeated darts at its real or reflected antagonist. But both, when taken out of each other's sight, instantly become quiet." The fighting-fishes, as the Siamese call them, are kept in globes like gold-fish, and fed from time to time with the larvæ of mosquitoes. The Siamese are as wild after their combats as the Malays are for cock-fighting, and often stake large sums, or even the freedom of themselves and their families, on the prowess and skill of a particular betta. The license to exhibit fish-fights is farmed by Government, and brings in a considerable revenue to the King of Siam.
Now, much the same thing happens on a lesser scale during the battles of the sticklebacks with their pugnacious rivals. It is then especially that their bodies assume the beautiful transparent and iridescent colors so poetically described by Mr. Warington. Their vitality rises to its highest point, and their eyes sparkle like a girl's at a ball with the most vivacious brilliancy. But when a hapless stickleback is conquered in the lists, says Mr. Darwin, "his gallant bearing at once forsakes him; his gay colors fade away; and he hides his disgrace among his peaceable companions, but is for some time the constant object of his conqueror's persecution."
It is pretty clear, then, that the stickles and lateral spines of the stickleback have been mainly developed, like the spurs and wing-weapons of birds, the tusks of boars, the antlers of deer, and the horns of lizards, for the purpose of combating rivals in these annual contests, and of securing the favor of the female fish. The same thing is also true of their beautiful colors, or rather, both are but different sides of the same question; for, as Mr. Wallace has shown, the most beautiful animal is also the strongest and most efficient, and the periods of high vitality are always accompanied by the most ornamental developments and the most vivid coloring. From generation to generation, the strongest, best armed, and most brilliant sticklebacks have conquered the feebler or uglier in battle, and have been selected as husbands by the greater number of their fastidious mates. None but the brave deserve the fair; and, among sticklebacks, none but the brave succeed in winning them. I do not doubt that the stickles also prove incidentally useful to the fish in protecting him from the attacks of larger predatory species; sticklebacks are seldom attacked by perch or trout, and an instance is on record where a pike has been choked by one of these tiny creatures, which erected its sharp spines in his throat as the greedy monster tried to swallow it; but this secondary purpose is only a derivative one; the spines themselves must originally have been developed, as in all other cases, for the wedding tournaments between stickleback and stickleback. It is thus that the horns and tusks of higher animals primarily produced in the internecine combats of the males are occasionally employed for external defense; thus that the spurs and beaks of birds are occasionally turned to the protection of their fledglings. But it may be laid down as a general law of biology, in spite of misconceptions and misstatements to the contrary, that no animal habitually and normally fights any other creatures except individuals of its own species. Dog fights dog, and tiger tiger; but game-cocks do not engage with turkeys, nor do stags usually join battle with buffaloes or bears.
As soon as the pairing-season sets in, the first care of the male stickleback is to provide a nest for his wife and children. For the stickleback is just as much a nest-builder as any bird; only, he does all the work himself, instead of being aided, as birds usually are, in
the task of nidification, by his attentive partner. He begins by busily collecting a quantity of delicate fibrous material, the tissues of water-weeds or of macerated land-plants, which he mats with his mouth into an irregular circular mass, somewhat depressed, and about an inch and a quarter in diameter. Then he covers the top with similar materials, and leaves in the center of one side a large, round aperture to act as a doorway. As he mats the fibers together by creeping over them with his body, he cements them firmly with the slimy mucus that exudes from his skin. He is a quick worker, not to say a jerry builder (any one can watch the whole process easily for himself in a fresh-water aquarium), and he only takes a few hours in getting the entire residence completed from basement to coping-stone. As soon as it is finished, the little architect sets out on his quest of a partner or partners ready to occupy it. If he meets a rival on the way, the two small Turks fight out their differences at once on the spot, while the bride-elect amicably stands by expectant, and accepts the conqueror. When she emerges from her hiding-place under the waving weeds and comes out, the guerdon of his prowess, to survey the nest he has deftly woven for her, the tiny sultan positively dances and curvets around her, "mad with delight," as an acute observer has well worded it. "he darts round her in every direction; then to his accumulated materials for the nest; then back again in an instant, and, as she does not advance, he endeavors to push her with his snout, and then tries to pull her by the tail and side-spine to the nest." Indeed, there is a deal more that is human and natural in the lives of all these little despised creatures than the people who laugh at theories of tittlebats have ever stooped to notice or discover.
As soon as the stickleback has duly inducted the partner of his choice with many caresses into the home he has built for her, or rather for her offspring, he introduces her by the door he has left in the side into the closed chamber. In a few minutes the bride has laid two or three tiny, transparent yellow eggs, after which she bores a hole with her snout on the side of the nest opposite to that by which she entered, and makes her exit, a divorced wife, without further formalities. "The nest," says Dr. Gunther, "has now two doors, and the eggs are exposed to the cool stream of water, which entering by one door flows out at the other." This, of course, by keeping up a fresh and constant current, supplies them with the oxygen necessary for hatching. Next day, the little sultan goes out again in quest of a fresh mate, and brings back his new bride to add a few more eggs to his stock of spawn. This operation he repeats daily until the nest is nearly full; and then the fond father sets to work himself at the congenial task of incubation. For among fish it is almost always the male, not the female, who sits upon the eggs and charges himself with the care and education of the young fry.
For the subsequent stages, I can not do better than quote Frank Buckland's animated account of a case observed by the learned curator of the Norwich Museum. "Nothing," says the genial naturalist and angler, "could exceed the attention from this time evinced by the male fish. He kept constant watch over the nest, every now and then shaking up the materials and dragging out the eggs, and then pushing them into their receptacles again and tucking them up with his snout, arranging the whole to his mind, and again and again adjusting it until he was satisfied; after which he hung or hovered over the surface of the nest, his head close to the orifice, the body inclined upward at an angle of about 45°, fanning it with the pectoral fins, aided by a side motion of the tail. This curious manœuvre was apparently for the purpose of ventilating the spawn; at least by this means a current of water was made to set in toward the nest, as was evident by the agitation of particles of matter attached to it. This fanning, or ventilation, was frequently repeated every day till the young were hatched; and sometimes the little fellow would dive head foremost into his nursery and bring out a mouthful of sand, which he would carry to some distance and discharge with a puff. At the end of a month the young ones were first perceived. The nest was built on the 28d of April; the young appeared on the 21st of May."
After the young are actually hatched, the fond parent only redoubles his delicate attentions. He never leaves the precincts of home by day or night; and he guards the nest with the utmost pertinacity, allowing no stray intruder from any side to approach it. If a greedy water-beetle or other enemy comes near the young, this exemplary father runs full tilt at him with his armed spines, pounces upon him broadside, and unceremoniously shoves or tumbles him over. If you try to disturb him in an aquarium with a stick or pencil, he will charge at it smartly, and strike it so hard that the blow can be distinctly felt by the hand that holds it. Among the enemies he has to repel on such occasions, I regret to say (for the honor of maternity I would fain conceal the fact), are the mothers themselves of his little charges, who wish to emulate Saturn and the common rabbit by making a dinner off their own flesh and blood. "For a whole month," says Dr. Gunther, "he watches over his treasure, defending it stoutly against all invaders, and especially against his own wives, who have a great desire to get at the eggs." Those unnatural parents, indeed, make such a dead set upon their young and the devoted father who guards them, that, as Mr. Darwin cynically observes, "it would be no small relief to him if after depositing their eggs they were immediately devoured by some enemy, for he is forced incessantly to drive them from the nest." Let us trust that the wedded stickleback himself never indulges in such uxoricidal fancies.
The fry, when hatched, are at first so very minute and transparent that you can with difficulty perceive them in the water of an aquarium, and even so only by the gentle fluttering motion of their wee fins. Their good papa continues, however, to perform the duties of a nurse for them with profound vigilance, confining them at first to the meshes of the nest, and, when they stray too far, gently leading them back with unremitting kindness to the path of duty. By degrees, as their knowledge of the world increases, he wisely allows them to indulge in greater excursions, and hollows out for them a small basin in the sand of the bottom, where they may disport themselves at their ease until they grow strong enough to venture on a wider range of thought and action. If rival papas or hungry mammas attempt to devour them, he falls upon the assailants in a violent fury, and carried away, it would appear, by the warmth of his feelings, occasionally goes so far as actually to indulge in acts of cannibalism. For this I do not commend him. No amount of ethical enthusiasm can ever justify a truly moral being in devouring the persons of his fallen enemies.
Fellows of the Royal Geographical Society are probably aware that in the neighborhood of London, and more precisely through the parish of Wandsworth, there flows a minor tributary of Thames, by name the Wandle. This stream, as the sportive youth of South London know full well, abounds in sticklebacks of all ages and sexes; and here it was that Mr. Smee, one of the chief contributors to the modern theory of tittlebats, first observed their habits and manners. "They are very pugnacious and cunning creatures," says he, in his charming work, "My Garden." "They build a nest and protect it. In the middle of May I observed a stickleback evidently guarding a circle of about two inches in diameter, and chasing away every other fish which came within his domain. On closer examination, I saw at the bottom a small circular plate of the same size, made of fiber, but arranged level with the bed of the stream. Suspecting a nest, I carefully raised it, when it proved to contain two parcels of eggs, which were about the size of a large pin's head. I immediately replaced the material as well as I could in its former place; but the stickleback was not at all satisfied with my arrangement, and set to work diligently to adjust it himself. He brought little bits of fiber and thrust them into the mass, and rearranged the larger fibers. When he was perfectly satisfied with what he had done, he mounted guard and rushed at any other fish which came near him. Afterward, I found these nests by scores, each protected by its guardian stickleback; and in the month of May I can always delight my visitors by showing them a nest presided over by the pugnacious little fish." I may add that similar nests are to be found in almost every brook or pond in England at the appropriate season: only, you must be born with the proper eye for seeing them. It is not every man who can discern stickleback. I once conducted a statistical survey of all the lizards inhabiting Great Britain and Ireland, and came to the conclusion, as the result of my census, that the lacertine population of the United Kingdom numbers at least two hundred million, or more than five times the human beings; and yet how often most people on their walks abroad meet a man, and how very, very seldom they happen upon a lizard!
Sticklebacks are not by any means the only fish which thus take care of their helpless progeny during the first weeks of infancy. It must be remembered that our acquaintance with the domestic habits and manners of fishes, and especially of the marine species, is but sporadic and fragmentary; opportunities for ohservation are rare on the sea-bottom, while, as for aquariums, the life there is so strained and unnatural that we learn for the most part little more from that source than one would learn of the intricacies of human existence by watching the interiors of prisons and of convents, But even among the few fish at all intimately known to us at present, there are several which deserve high commendation for their able and conscientious discharge of their paternal duties. Certain cat-fish, for example, and many other species, construct nests like good fathers, and guard the spawn deposited in them by their unnatural spouses. One siluroid bearing the suggestive classical name of Arius actually carries the eggs about with him in his own mouth, and there devotedly hatches them. There is a fish of the Sea of Galilee, locally supposed to be the very kind from whose mouth St. Peter took the miraculous denarius for the payment of the apostles' tribute, and this pious and well-principled creature (even his scientific name is Chromis sacra) holds his eggs in the same fashion, and hatches them out in his capacious pharynx. Among the pipe-fish and sea-horses, including the well-known hippocampus of the Mediterranean and the Westminster Aquarium, Nature has gone one step further in the direction of parental supervision. These fish have a regular pouch like the kangaroo, in which the excellent papa retains the young till they are of full age to shift for themselves.
Yet even here it is the fond father, not the gay and careless mother, who wheels about the family perambulator: only two known cases occur among fish where the mother takes any part at all in the hatching or education of her own young. One is a cat-fish from British Guiana, whose under surface becomes soft and spongy after the spawning-season. The mother, as soon as she has laid her eggs, presses them hard into this spongy integument by lying on top of them. There they stick, and she carries them about in the pits thus formed, much as the familiar Surinam toad carries about her hatching ova and tadpoles in the skin of her back. The other instance is that of a singular pipe-fish from the Indian Ocean, who forms a pouch for her young by allowing her ventral fins to coalesce with the soft skin of her under surface. These two examples of devoted maternity, however, scarcely suffice to absolve the mother-fish as a class from the general charge of heartless desertion brought against them by modern ichthyologists.
It is worth while, perhaps, to note in passing (since a theory of tittlebats is nothing if not exhaustive) that the eggs of stickleback are larger in proportion to the size of the full-grown individual than those of any other known fish. Why is this? Simply because the stickleback are good fathers, who take great care of their callow young. (I don't know what callow means, as applied to a fish, but I feel sure it is a neat and appropriate epithet.) Where the chances of infant mortality rule high, the mother-animal must produce vast numbers of small and ill-supplied eggs in order to provide against the adverse possibilities. That careless parent, the cod, who lays her spawn unprotected upon the shallow banks, for thousands of greedy enemies to devour, often produces at a single birth as many as from four to nine million separate eggs. But just in proportion as the eggs and young are more efficiently guarded and provided for in life does it become possible to economize in the number of germs originally produced, and to give each at the outset a fair supply of yolk to start well in life with. Compare the myriad tiny black seeds of the poppy, which take their even chances anywhere that fate may carry them, with the richly stored bean or pea or filbert, well provided with nutriment for the growing seedling, and you will see at once the force of the analogy here intended. The codfish lays a great many ill-supplied eggs, and lets them shift for themselves in the open sea as best they may, on the off chance of one among four million or so reaching maturity; the stickleback lays comparatively few large and well-supplied eggs, but the amiable father watches with tender solicitude over the safety of all, so that on an average two at least out of each mother's small brood must needs survive to years of adult sticklebackhood.
I have spoken of the stickleback genus so far as though, like the French Republic, it were one and indivisible. Such, however, is not the case. The family has split up into several minor sections, each adapted to particular situations. There are some ten known species of stickleback, and the facts hitherto noted apply most especially (save in a few instances) to one above all others among them, the common British three-spined stickleback. All the varieties are pretty much alike in all essential points, having the same long, flat-sided bodies, with hard cheeks, while parts of the skeleton usually form an external coat of mail, and grow out into large scutes or shields along the sides. On their back are more or fewer of the spines from which the entire group take their generic name, nine in one species, fifteen in another, three only in the commonest English form, and no more than two in the pretty little North American example. One of them has adapted itself to brackish water and the open sea; the others are all fresh-water forms, though most of them at a pinch can manage a sea-voyage without serious damage to their constitutions. They are a north temperate family by origin; in other words, they have sprung up in the rivers of the sub-Arctic zone, and have not yet spread beyond the Arctic and temperate regions of the northern hemisphere on both sides of the Atlantic.
Our common little British river stickleback, the familiar tittlebat of the Serpentine and the Hampstead Ponds, is the three-spined form (Gastrosteus aculeatus); and he has generally, in addition to his offensive spines, a series of defensive shields or plates along the gleaming side of the body. In Central Europe, however, these shields generally disappear, I suppose through the absence of some dangerous enemy to whose attacks the little creature is habitually subject in our British waters. This last idea, however, must be accepted as purely theoretical for I can not suggest who that enemy may be. The three-spined stickleback is a very active and voracious little fellow, exceedingly destructive to the fry of carp or trout, and therefore, of course, highly detrimental in ponds where the preservation of larger fish is a matter of interest. It is scarcely to be conceived, says our great piscicultural authority, Dr. Günther, what damage these little creatures do, or how prejudicial they are to the increase of all the other fishes among whom they live. Their industry, sagacity, greediness, and success in seeking out and destroying all the young fry that come in their way are indeed simply marvelous. To take a single instance, a small three-spined stickleback kept in an aquarium devoured in five hours' time, by actual observation, seventy-four young dace, each a quarter of an inch long. Two days after, the same unconscionable little gourmand swallowed sixty-two, and seemed as hungry at the end of that bout as if he had never tasted breakfast. Considering that stickleback sometimes simply swarm in rivers, ascending them facto agmine in amazing shoals, the damage they are calculated to do to the trout and bream fishery can only be adequately known to Professor Huxley, who has long and truly urged that the number of fish caught or destroyed by man's will sinks into what the French scientists call une quantité négligeable by the side of the havoc everywhere wrought through the natural enemies of each species.
Our other native British fresh-water kinds are the nine-spined stickleback (commonly called the ten-spined out of pure cussedness) and the four-spined, also known as the smooth-tailed, though authorities differ much as to the division of species, some making many and some few. The nine-spined variety is a very small kind, more or less estuarine and semi-marine in his tastes, a frequenter of the river-banks about Southend and Chatham, and much given to migrating in shoals up the creeks and backwaters in early spring. He can also generally be discovered at the Ship or the Trafalgar during the fish-dinner season, trying to pass himself off in good company as a distinguished fish among a plateful of whitebait; but his imposture may be easily detected by observing the tiny stickles on his back, which are too small, indeed, to make him unpleasant eating, but quite big enough to prevent him from giving himself any aristocratic airs on the strength of his resemblance to a parliamentary delicacy. His sides are perfectly smooth and unprotected, and he may be investigated by the curious, nest and all, nearly everywhere among the brackish marshes of the Thames estuary.
The fifteen-spined stickleback or sea-adder is our one marine English species, common on many parts of the British coast, and specially observed by competent naturalists in Cornwall and the Orkneys. This salt-water descendant of the little river tittlebat grows, as might naturally be expected, to a larger size in his more spacious environment, and reaches the dimensions of an average trout. He never ascends rivers, even to spawn, but weaves his nest of sea-weed or corralline under some overhanging ledge, and guards his bright, amber-colored eggs with the same jealous care as his fresh-water relations. His personal appearance is chiefly remarkable for the very elongated form which procures him the name of adder, as well as for the prolonged snout, not unlike a gar-fish, and the rows of shields that protect his side with a perfect coat of sheeny sheet-armor. That admirable observer, Mr. Richard Couch, of Mevagissey, to whom, with Mr. Jonathan Couch, we owe most of our knowledge of marine fish-life, was the first to watch his manner of nesting. He found that the marine stickleback built its home in shallow water, where the bottom was thickly covered with sea-wrack, and that it bound the materials together with an elastic thread, resembling silk, which hardens by exposure to water, but the mode of whose secretion has not yet been determined. Mr. Couch visited one of the nests every day for three weeks, and saw the parent stickleback invariably mounting guard over it with military precision. When he ventured to disturb part of the materials, the fish immediately set about repairing the damage, by drawing together the sides of the opening, so as to conceal once more the eggs which the too curious naturalist had exposed to view. Stickleback will tolerate no eaves-dropping intrusion into the sacred privacy of domestic life. Society journalism is quite unknown among them.
These few remarks complete in outline the theory of tittlebats which I venture tentatively to suggest in substitution for Mr. Pickwick's lost and lamented essay. As its moral may not be immediately apparent to the young, the gay, the giddy, and the thoughtless, I shall not hesitate to append one in the undisguised form borrowed by modern ethical writers from Æsop's fables. If any of my didactic reflections scattered through the text shall have induced only one serious stickleback to abandon polygamy or to renounce cannibalism, I shall feel that this article has not been written in vain.—Cornhill Magazine.