Part 48

Snakes, like lizards, are very commonly colored in such a way that they may harmonize with their surroundings. A good many poisonous forms, on the other hand, advertise their dangerous properties by brilliant hues and striking patterns. Such “warning coloration” is seen, for example, in the coral snakes of tropical America, which are marked with broad red rings, alternating with others of whitish tint, shading into black at the front and back of each ring. These coral snakes serve as models which certain harmless forms unconsciously mimic, thus securing a certain amount of immunity from attack by sailing under false colors.

SOME SNAKES THAT WARN

In the American rattlesnakes, at each periodical casting of the skin or slough, a little knob remains at the end of the tail. A series of these loosely united together make up the “rattle,” used for the production of warning sounds. The “hissing” of a snake has the same purpose. Venomous snakes also commonly assume a warning attitude, raising the front part of the body from the ground and, in some cases, as illustrated by the cobra, inflating a kind of hood--in this particular instance bringing a black, spectacle-shaped mark into prominence.

But in these and other animals it must not be supposed that the “warning” is for the benefit of the prey, but may be taken as a hint to aggressive birds and mammals that discretion is the better part of valor. The success of this device is shown by the terror with which all monkeys regard serpents.

THE ART OF SNAKE CHARMING

This art has been practised from very ancient times in Africa and the East, and often remains from generation to generation the profession of a family. It is sometimes practised for alleged useful purposes, since the “charmers” are often employed to clear a house of its unwelcome snake visitors. For the most part, however, it is, like conjuring, a form of popular amusement. In India it is practised by several distinct classes of men, who vary in the methods and success of their art. The charmers usually take good care to play with snakes whose fangs or even poison-glands have been carefully removed, or even to use those which are not venomous at all. The frequent use of a musical pipe, and the way in which the snakes seem to respond to the sounds, are facts interesting to naturalists, who believe that at least many snakes are very deaf. The charmers sometimes manifest a fearlessly confident dexterity in handling intact venomous snakes.

THE WISDOM OF THE SERPENT

In correlation with the presence of a well-developed brain, snakes may be regarded as the most intelligent of reptiles, though the idea of their “wisdom” probably took origin in their stealthy ways, and the curious “fascinating” powers already mentioned. They are among the numerous animals that have been the objects of superstitious worship.

AMERICAN AND OTHER SNAKES

The group of North American snakes include a large number of Colubrine snakes and about a score of pit-vipers or rattlesnakes. Among the Colubrine forms are the water-snakes, the black snakes and coachwhip snakes of the genus Coluber, the pine-snakes, the king-snakes, the ring-necked snakes and so on. Besides the rattlesnakes proper, there are the related copperheads and mocassins. Outside these two families there are the boa-like and venomous coral-snakes, and the harlequin snake.

There are no snakes in Ireland, nor are they represented in most oceanic islands such as New Zealand and Iceland. The pythons and boas are distinctly tropical snakes: the pythons in Africa, India, Malaya, Australia; the boas in tropical America. Among the most important venomous snakes of India are the following: the cobra, the Hamadryas, the Krait, the Sankni, and the sea-snakes.

_AMPHIBIANS_ (_Amphibia_)

FROGS, NEWTS, SALAMANDERS AND TOADS

The amphibians hold a middle position between the reptiles and fishes. The name, Amphibia, means “double-lifed” or living on both land and water. The larvæ, after leaving the eggs, live in the water like fishes; they gradually accustom themselves to live in the air, and when their metamorphosis is complete they breathe by means of lungs.

They have red, cold blood, and are enveloped in a smooth, often slippery, skin. Some have tails, like the newt and salamander, and others are tailless, like the frog and toad.

=Frog= (_Rana temporaria_) is familiar all over America, and is found in the early spring in all our ponds, ditches, and lakes, in which also large quantities of frog’s eggs can be seen. When fully developed, frogs have a short, tailless body, a large head, and four legs, the toes being frequently joined together by a membrane.

They deposit their eggs (_a_) in the water, either in masses or in strings. The larvæ (called tadpoles) have a long, flattened tail (_c_); they have no legs, and breathe through gills (_b_), and are therefore very different from the fully developed frog. The gills gradually disappear, and lungs are developed; the fore legs make their appearance, the hind pair developing first (_d_ and _e_); the tail gradually diminishes, and finally disappears (_f_). The change, is then complete, and the young frog leaves the water to begin its life upon land. The common frog leaves the water immediately after spawning, and makes itself very useful by destroying numerous injurious insects and snails.

In this country the commoner species of frogs embrace the BULL FROG (_R. catesbiana_), which is the largest, sometimes being eight inches long. Its sonorous bass notes are familiar to the ear, and to the eye it presents a greenish appearance, brightest on the head; with faint spots on the back and blotches on the legs. It occurs from Kansas eastwards, and its hind-legs fried are considered a delicacy.

The SPRING FROG (_R. clamatans_) is widespread, about three inches in length, green and black spotted above and white below.

The common GREEN FROG (_R. virescens_) has irregular black blotches, and is paler beneath. Both average about three inches in length.

The PICKEREL FROG (_R. palustris_) is light brown in color, with two rows of large oblong blotches of dark brown on the back and spots elsewhere. It is smaller in size and less aquatic than most other kinds.

The WOOD-FROG or TREE-FROG (_R. sylvatica_) is more closely related in structure to the toads than to the frogs proper. The tree-frogs show various interesting adaptations to their arboreal life. The last joint of each toe bears a claw, on which is supported a disc or sucker by means of which the animals can cling to a perfectly perpendicular surface. Most of them also exhibit in a greater or less degree the power of color-change, where the color varies from a dark brown to a lichen-like gray or a brilliant green.

=Newts= are separated from the lizards on account of their changes while young. Like the frogs, they are first tadpoles, and do not assume their perfect shape until six weeks after their exclusion from the eggs. The common Newt is a beautiful inhabitant of the ponds, ditches, and still waters.

The male newt is distinguished by a beautiful crimson tipped wavy crest of loose skin, that extends along the whole course of the back and tail, and which, together with the rich orange-colored belly, makes it a most beautiful creature. The female has a singular habit of laying her eggs upon long leaves of water-plants, and actually tying them in the leaf by a regular knot.

=Salamander= (_Salamandra maculata_) is a nocturnal animal, and found in woods and hedges under decayed leaves and similar matter. Their bodies are longer and similar to the lizard. Most of the species lay eggs, usually in the water. From these the gilled young hatch out. They are carnivorous or insectivorous. In the adult stage, some are aquatic, but more live on the earth burrowing beneath the soil or under stones, seeking their prey at night. None are poisonous, except that they have glands in the skin which secrete an acrid juice. Our largest species is the mud puppy (_Necturus_) of the Mississippi basin; the largest living species is the giant salamander of Japan, three feet in length.

=Toad= (_Bufo_).--Toads are distinguished from frogs by the absence of teeth, by the roughness of the skin, by peculiarities in the breastbone, and by the shorter hind-legs.

The common toad is a shy, nocturnal animal, hiding during the day in dark, damp places, crawling about at night in search of insects, grubs, slugs, worms, and the like. Its appearance is familiar--a dirty brownish-gray color, a warty skin, a flat head, swollen parotid glands above the ears, bright jewel-like eyes with a transverse pupil, slightly webbed toes. They are heavier and clumsier than frogs, and cannot leap nearly so far. During the winter they live in the mud or in holes. In spring they pair, and the females lay in the water-pools their numerous eggs in strings about three or four feet in length. The tadpoles are smaller and darker than those of frogs, and do not accomplish their transformation into toads until autumn.

Toads are widely distributed over most parts of the continents, but are most abundant in tropical regions. The common toad of North America ranges everywhere east of the Rocky Mountains. In the Southern States another very similar species is numerous, and other species are found in the West. The largest toad of tropical America measures eight inches in length.

The LAUGHING TOAD (_Bombinator igneus_) is the smallest of the toads, with a yellow spotted belly.

_THE FISHES_ (_Pisces_)

The fishes are the last class of the vertebrated animals, and have cold, red blood. The elongated body generally tapers off to the tail; the head and neck are large; the limbs are called fins, and are such as to make efficient paddles. They are usually one or more fins in the middle line of the back and one or two in a corresponding position beneath the tail (anal fins); while the tip of the tail is terminated by a caudal fin, the chief organ of swimming. All of the fins are supported by a skeleton of rays, either horny or spinous in character.

There are but two chambers to the heart, and the occurrence of a swim bladder, an organ for regulating or recognition of the depth of the water in which the fish is, is very frequent. Externally fish have a defensive armor of scales or bony plates embedded in the skin. They breathe throughout life by means of gills, which are delicate folds or filaments connected with openings (gill slits) in the sides of the throat. The fishes live in water, and reproduce their species by eggs.

There are several great groups of fishes, distinguished by the presence of a cartilage or bony skeleton, by having the gill slits free or under a gill cover, by characteristics of the skull, presence or absence of air bladder, and by peculiarities of the digestive tract and nervous system.

(1) The bony, or true fishes (_Teleostei_), which include all the most familiar freshwater and marine forms; (2) the Cartilaginous fishes (_Elasmobranchii_), including sharks, dog-fish, bays and skates; (3) the heavily-armored fishes (_Ganoidei_), like the sturgeons and bony pike; and (4) the double-breathers (_Dipnoi_), of rare occurrence.

=THE BONY FISHES= (_Teleostei_)

These have a bony skeleton, and a well-defined vertebra, or backbone; their bodies are mostly covered with scales.

=Alewife= (_Alosa tyrannus_), a fish of the same genus with the Shad, which, at the beginning of summer, appears in great numbers on the east coast of North America, and enters the rivers to spawn. It appears in Chesapeake Bay in March, on the coasts of New York and New England in April, and on those of the British provinces about May 1. It abounds in the bay of Fundy, but is more rare in the gulf of St. Lawrence; and the bay of Miramichi appears to be its northern limit. Its length is not more than twelve inches. The alewife is called spring herring in some places, and gaspereau by the French Canadians.

=Bass= (_Labrax_) is a member of the perch family. The shape is salmon-like. The color is without the zebra-like bars of the perch, and shades off from dusky blue above to silvery white beneath.

The Striped Bass or Rock-fish of the United States (_L. lineatus_) very nearly resembles the common bass, but attains a larger size. It is one of the most important of American food fishes, and sometimes weighs fifty pounds. It is caught from July to September. The name Stone Bass is given to various forms. A Yellow Bass is found in the Lower Mississippi valley, and the Fresh-water Bass is an imported fish found in the streams of eastern New York and the other middle states.

=Bluefish= (_Temnodon or Pomatomus saltator_).--A fish common on the eastern coasts of America, allied to the mackerel. The only known species is abundant on the east coast of North America. The upper parts are of a bluish color, the lower parts whitish, a large black spot at the base of the pectoral fins. The mouth is crowded with teeth, the jaws are furnished with large ones. The bluefish preys on other fishes, such as the menhaden and mackerel, the shoals of which it pursues. It sometimes attains a length of three, or even five feet, and a weight of fourteen pounds. It is often caught by trolling, as it bites readily at an object drawn swiftly through the water. It is much esteemed for the table.

=Bullhead.=--In the United States the name is given to some species of catfish or horned pout; in England to a smaller fish, allied to our miller’s thumb, but belonging to a different group from the catfish.

=Carp.= See page 256.

=Cod= (_Gadus_), a genus of bony fishes in the soft-rayed order. This is probably the most important food fish and is taken in enormous numbers on the coasts of Europe and of eastern North America. It occurs in the northern Pacific as well. It feeds upon other fishes as well as on shellfish, and large specimens weigh over one hundred pounds. Allied to the cod are the haddock, pollack, hake and cusk.

=Eel= (_Anguilla vulgaris_) has elongated form, and has become proverbial on account of its slipperiness and tenacity of life. In the rivers and lakes only female fish are found; the males keep to the open sea. The former go down to the sea in the autumn; but in the following spring the young female fish swim up the rivers in immense numbers, while the young males remain in the sea. During the day the eel conceals itself in the mud, but at night it exhibits its voracious qualities by swallowing numerous fish, water insects, crabs, mussels, and worms. Its firm, delicate flesh is much esteemed.

=Flounder= (_Pleuronectes flesus_), a common species of flat-fish, of wide distribution in shallow waters in north temperate countries. It is the Scotch “fluke,” and the Swedish “flundra,” and differs but a little from the plaice and dab, two of the commonest neighbor-species. Like other flat-fishes, the flounder is asymmetrical, and swims or rests on one side, almost always the left, the eye of which is in early youth, brought round to the upturned surface. It measures about one foot in length, and about a third as much between the dorsal and the ventral edge, without including the fringing fins.

Of the two dozen related species, the plaice, the dab, the smear-dab, and the craig-fluke are the commonest.

=Flying-fish.=--Various fishes which have the power of sustaining themselves for a time in the air by means of their large pectoral fins. Generally, however, the name is limited to the species of the genus _Exocoetus_, which belongs to the family of mackerel-pikes. These can pass through the air to a considerable distance, sometimes as much as two hundred yards, to escape from the attacks of other fishes, especially the dolphin. They are most common between the tropics.

=Goldfish.= See page 256.

=Haddock= (_Gadus æglefinus_) is a fish of the same genus as the cod, and much resembling it in general appearance; but distinguished by a notched tail and a white line along the side. In habits the two are much alike, being voracious, eating anything edible, but largely clams and the like.

=Halibut= (_Hippoglossus vulgaris_), the largest of all the flat-fish and in form more elongated than the flounder or the turbot. The halibut, though esteemed for the table, is not to be compared in quality with the turbot; its flesh is white and firm, dry and of little flavor. It attains a great size; specimens have been caught weighing at least five hundred pounds, and one caught in Iceland was little short of twenty feet long.

=Herring= (_Clupea harengus_) belongs to the order of bony fishes and is spread over the whole North Atlantic. It is of great economic importance, and occurs in large schools, swimming through the sea with open mouths, scooping up the minute life for food. Immense numbers are taken both here and abroad, the annual catch for Europe and America being estimated at a billion and a half pounds. The young are also taken in vast quantities and are preserved as American sardines. With us most of the adults are smoked and dried.

=Mackerel= (_Scomber_), a genus of fishes which also includes the tunny, bonito, and sucking fishes. It is an important food fish occurring in the North Atlantic and characterized by its slender shape, the series of little finlets on the tail and the deeply notched caudal or tail fin. It is taken both by hooks and by seines. Some are eaten in the fresh condition and some are salted. It goes in large schools. Allied is the Spanish mackerel of our southern waters and the large horse mackerel which is more common in the Mediterranean, where it is called the tunny.

=Perch= (_Perca_).--Spiny-finned fishes, well represented by the Fresh-water Perch (_P. fluviatilis_), which is widely distributed in lakes, ponds, and rivers in Europe, Northern Asia, North America and Britain. It is of a greenish-brown color above and golden yellow on the under parts, with six or seven indistinct dark bands on the back. In length it measures about eighteen inches, and its height is about a third of this. It sometimes weighs from three to five pounds, and a prize of nine pounds has been recorded.

=Porgy.=--A food fish on the eastern coast from Cape Cod south, known also as scup. It should not be confounded with the pogy or menhaden, one of the herrings, which is taken extensively for oil.

=Pollack= (_Gadus pollachius_), a fish, belonging to the cod genus. It is about the size of the coal-fish, is active in habit, and is frequently caught. The lower jaw projects beyond the upper, and there is no barbel. It has commercial value in the English Channel and off the coasts of Newfoundland. Allied species, which promise a valuable future, abound from Puget Sound to Alaska on the Pacific coast.

=Salmon= (_Salmo_), a genus of well-known fish which inhabits both salt and fresh waters, and ranks among the food-fishes. It generally attains a length of from three to four feet, and an average weight of from twelve to thirty pounds, but these limits are frequently exceeded. The adult fish is a steel-blue on the back and head, becoming lighter on the sides and belly.

It usually continues in the shallows of its native stream for two years after hatching, and during this period it attains a length of eight inches. When the season of its migration arrives, the fins have become darker and the fish has assumed a silvery hue. It is now known as a _smolt_ or _salmon fry_. The smolts now congregate into shoals and proceed seaward. On reaching the estuary they remain in its brakish water for a short time and then make for the open sea. Leaving its native river as a fish weighing, it may be, not more than two ounces, the smolt, after three months’ absence, may return to fresh water as a _grilse_, weighing four or five pounds. In the grilse stage, the fish is capable of depositing eggs. After spawning in the fresh water the grilse again seeks the sea in the autumn, and when its second stay in the ocean is over it returns after a few months’ absence as the adult salmon, weighing from eight to ten pounds. The salmon returns as a rule to the river in which it passed its earlier existence. The fertility of the fish is enormous.

Salmon are caught by the rod, and by means of nets, the fishings being regulated by law. There are important fisheries in some European and North American rivers. In Europe the fish is found between the latitudes of forty-five and seventy-five degrees, in North America in corresponding latitudes. The flesh when fresh is of a bright orange color, and is of highest flavor when taken from the sea-feeding fish. In the waters of northwestern America are several salmon belonging to a distinct genus, including the quinnat or king-salmon, blue-back salmon or redfish, silver salmon, dog salmon, and humpback salmon. The quinnat has an average weight of twenty-two pounds, but sometimes reaches one hundred pounds. Both it and the blue-back salmon are caught in immense numbers in the Columbia, Sacramento, and Frazer rivers (especially in spring), and are preserved by canning.

=Sardine, or Pilchard= (_Clupea pilchardus_) is an important fish closely related to the herring and sprat. In size it grows from ten to fourteen inches; in color it is bluish-green above, whitish underneath and on its sides. It is entirely marine in habit, and its eggs float on the surface of the sea, unlike those of the herring, which are attached to objects at the bottom. The young, before it has attained maturity, is known as the sardine, and as such forms a valuable fishery; the full-grown pilchard is used as an article of diet as well as for bait. The method of capture is usually by drift-net. It is most abundant off the coasts of Portugal, and in the English Channel and the Mediterranean.

=Shad= is a migratory fish of great food value. It ascends all of the rivers of the eastern coast of the United States every spring to lay its eggs. It is closely related to the herring, but is much larger, and were it not so full of bones it would stand very near the head of food fishes.

=Smelt= (_Osmerus_) is a genus of the Salmon family, characterized by strong fang-like teeth, and by rather large scales, which readily fall off. The form is very trout-like, but rather more slender; the tail is larger in proportion, and more forked. The back is whitish, tinged with green; the upper part of the sides shows bluish tints, the lower part of the sides and the belly are of a bright silvery color. The smelt has a peculiar, cucumber-like smell, and a delicious flavor, on account of which it is highly esteemed for the table.

=Sole= (_Solea_) is a fish oval in shape, the outline of the snout being semi-circular, and projecting somewhat beyond the mouth. The Common Sole (_S. vulgaris_) is a fish of high value in European markets. It lives in European seas from the Mediterranean to the north of Denmark, and is rarely caught on the American side of the Atlantic Ocean, although numerous closely allied kinds abound.

=Sword-fish= (_Xiphiidae_) are abundantly represented in tropical and subtropical seas. They are among the largest bony fishes, sometimes measuring twelve to fifteen feet in length. The sword, which may be over three feet long, is formed from a compressed prolongation of the upper jaw, and is often strong enough to stab whales fatally, or less advantageously to pierce the bottom of a ship or the planks of a boat. Sword-fish are said to attack whales and other cetacea, and also boats and canoes, and even large vessels.