TOAD. 318 TOADFLAX. captured mainly during twilight and at night. The list of known foods embraces every sort of insect and larva that can be captured, including many most injurious to horticulture ; and there is no doubt that a reasonable number of toads in a garden gives a valuable assistance in keep- ing down pests. They do no harm at all. They molt the outer skin several times a year, strug- gling out of it, and then swallowing it. When cold weather comes on they dig a hole in the ground, or find some warm, dry crevice among rocks, in a cellar or the like, and become dor- mant. This power of hibernation, and their ability to endure deprivation of food and water, tend to a longevity very unusual in so small an animal, for toads under favorable conditions will live thirty years or more. The stories told of buried toads surviving for long intervals in solid clay, rock, and the like, are usually un- worthy of belief. Experiment has shown that no toad can long endure deprivation of air, water, and food, although Buckland found that speci- mens immured in blocks of porous stone and buried in moist soil remained alive after eighteen months. As soon as the to;.ds emerge in the early spring their melodious piping is heard, and they make their way to water, where fighting between males and the mating of the sexes begin. After a few days long gelatinous ropes of black holoblastic eggs,' each about one-fifteenth of an inch in di- ameter, are to be found coiled or matted in warm ponds and roadside pools. Each female begins to breed when about four years old, and lays six to ten thousand eggs annually. These eggs rapid- ly increase in size, and hatch in four weeks or less, according to weather. A detailed history by R. Wright of their development may be found in the Standard Xatural History, vol. iii. (Bos- ton, 1885). The larviB are considerablj' advanced when freed from the egg, and are provided wuth a peculiar temporary organ in place of the yet undeveloped mouth, bj' which they cling to weeds and similar supports; and with bushy external gills as breathing organs. There is no trace of limbs, but a swimming organ is present in the form of a large fin-bordered tail. Development proceeds rapidly. The true mouth is soon formed, and the tadpoles begin to feed upon the minute algaa coating the bottom and floating on the sur- face, and later eat animal substances. They are the best scavengers for an aquarium. They keep in shallow water near shore, but are preyed upon by newts, turtles, fishes, and predaceous aquatic insects. Gradually growth advances, the fore legs appear, and later the hind legs are developed and the tail and gill-tufts are gradually absorbed. (For experiments in rear- ing tadpoles inider various food-conditions, see Factors of Evolution, under Evolution.) By midsummer the limbs are perfected, lungs have been formed, the tail is reduced to a mere stump, and the tadpoles creep out of the w-ater as small toads. Here they encounter a host of enemies, birds, snakes, turtles, etc,, so that a very small proportion escape to develop into adulthood, when they have few enemies except snakes. The common toad of the Old World (Bufo vulgaris) is very similar to the American toad. It inhabits almost the whole Pahearctic region, eastward to China and Japan. India and the Malay Archipelago have a widely prevalent and very rough-skinned species (Bufo melanostictus) , which has considerable power of changing color. The green toad of the Mediterranean region {Bufo viridis) is highly variable in color; and the natterjack and panther toads (qq.v.) of Western Europe nrach resemble it. The largest member of the genus is the huge agua toad of tropical America. ( See Agua. ) Various more distantly related amphibians are called 'toads,' as for example 'tree-toads' (see Hyla; Tree- Frog) ; the South American horned frogs (q.v.) of the cystignathine genus Ceratophrys; the Surinam 'toad' (see PiPA), and others. Compare Feog; Spadefoot. Fossil toads are quite rare, but are found scattered through the Tertiary formations from the Eocene upward, especially in Europe. Some very fine skeletons of toads, and even remains of tadpoles, have been found in the fresh-water ^Miocene deposits of Germany. Consult: Cope, Batrachia of North America (Smithsonian Institution, Washington, 1889); Boulenger, Tailless Butrachians of Europe (Ray Society, London, 1890) ; Kirkland, "Habits, Food, and Economic Value of the American Toad," in Bulletin JfG, Hatch Experiment Sta- tion (Amherst, Mass., 1897); Gadow, Amphibia and Reptiles (London, 1901). See accompanying Colored Plate. TOAD BUG. Any of the curious heterop- terous insects of the family Galgulid*. They have a short, broad body, projecting eyes, and dull, mottled colors, suggesting a miniature toad. They live in moist places along the banks of streams and ponds. About twenty species are known, of which three inhabit the United States. Our commonest sjjecies is Galgulus oculatus. TOADFISH, or Sapo. One of a family (Batrachoidid;T') of fishes allied to the gobies, tlie young of which fasten themselves to rocks by a central disk which is soon lost. They are f' r- ' •«," fj %^ -t'-A A TOADFISH. small carnivorous and scavenging coast fishes of all warm seas, abundant about weedy rocks and coral reefs. They have a robust form, are inac- tive, and resemble toads in the mingled browns and yellows of their coloration. The species il- lustrated {Opsanus pnrdus) inhabits the Gulf of Me.xico. TOADFLAX, or Butter-axd-Egg.s (Linaria). A genus of plants of the natural order Scrophu- lariaces, distinguished chiefly by the spur at the base of the corolla and the capsule opening by valves or teeth. The species are herbaceous, na- tives chiefly of the colder and temperate parts of the Old World. Common toadflax (Linaria viil- (laris) has an erect stem one to three feet high, with glaucous, linear-lanceolate leaves which thickly cover the stem, and terminal spikes of yellow flowers. It grows in fields along roadsides, etc., in Europe and America, where it has been introduced and where it is usually considered a troublesome weed. A very remarkable mon-
