The Common Toad

III. Batrachian Study

Teacher’s Story

“The toad hopped by us with jolting springs.”—Akers.

HOEVER has not had a pet toad has missed a most entertaining experience. Toad actions are surprisingly interesting; one of my safeguards against the blues is the memory of the thoughtful way one of my pet toads rubbed and patted its stomach with its little hands after it had swallowed a June-bug. Toads do not make warts upon attacking hands, neither do they rain down nor are they found in the bed-rock of quarries; but they do have a most interesting history of their own, which is not at all legendary, and which is very like a life with two incarnations.

The mother toad lays her eggs in May and June in ponds, or in the still pools, along streams; the eggs are laid in long strings of jellylike substance, and are dropped upon the pond bottom or attached to water weeds; when first deposited, the jelly is transparent and the little black eggs can be plainly seen; but after a day or two, bits of dirt accumulate upon the jelly, obscuring the eggs. At first the eggs are spherical, like tiny black pills, but as they begin to develop, they elongate and finally the tadpoles may be seen wriggling in the jelly mass, which affords them efficient protection. After four or five days, the tadpoles usually work their way out and swim away; at this stage, the only way to detect the head, is by the direction of the tadpole’s progress, since it naturally goes head first. However, the head soon becomes decidedly larger, although at first it is not provided with a mouth; it has instead, a V-shaped elevation where the mouth should be, which forms a sucker secreting a sticky substance by means of which the tadpole attaches itself to water weeds, resting head up. When two or three days old, we can detect little tassels on either side of the throat, which are the gills by which the little creature breathes; the blood passes through these gills, and is purified by coming in contact with the air which is mixed in the water. About ten days later, these gills disappear beneath a membrane which grows down over them; but they are still used for breathing, simply having changed position from the outside to the inside of the throat. The water enters the nostrils to the mouth, passes through an opening in the throat and flows over the gills and out through a little opening at the left side of the body; this opening or breathing-pore, can be easily seen in the larger tadpoles; and when the left arm develops, it is pushed out through this convenient orifice.

When about ten days old, the tadpole has developed a small, round mouth which is constantly in search of something to eat, and at the same time constantly opening and shutting to take in air for the gills; the mouth is provided with horny jaws for biting off pieces of plants. As the tadpole develops, its mouth gets larger and wider and extends back beneath the eyes, with a truly toadlike expansiveness.

At first, the tadpole’s eyes are even with the surface of the head and can scarcely be seen, but later they become more prominent and bulge like the eyes of the adult toad.

The tail of the tadpole is long and flat, surrounded by a fin, thus making an organ for swimming. It strikes the water, first this side and then that, making most graceful curves, which seem to originate near the body and multiply toward the tip of the tail. This movement propels the tadpole forward, or in any direction. The tail is very thin when seen from above; and it is amusing to look at a tadpole from above, and then at the side; it is like squaring a circle.

There is a superstition that tadpoles eat their tails; and in a sense this is true, because the material that is in the tail is absorbed into the growing body; but the last thing a right-minded tadpole would do, would be to bite off its own tail. However, if some other tadpole should bite off the tail or a growing leg, these organs conveniently grow anew.

When the tadpole is a month or two old, depending upon the species, its hind legs begin to show; they first appear as mere buds which finally push out completely. The feet are long and provided with five toes, of which the fourth is the longest; the toes are webbed so that they may be used to help in swimming. Two weeks later the arms begin to appear, the left one pushing out through the breathing-pore. The “hands” have four fingers and are not webbed; they are used in the water for balancing; while the hind legs are used for pushing, as the tail becomes smaller.

As the tadpole grows older, not only does its tail become shorter but its actions change. It now comes often to the surface of the water in order to get more air for its gills, although it lacks the frog tadpole’s nice adjustment of the growing lungs and the disappearing gills. At last some fine rainy day, the little creature feels that it is finally fitted to live the life of a land animal. It may not be a half inch in length, with big head, attenuated body and stumpy tail, but it swims to the shore, lifts itself on its front legs, which are scarcely larger than pins, and walks off, toeing in, with a very grown up air, and at this moment, the tadpole attains toadship. Numbers of them come out of the water together, hopping hither and thither with all of the eagerness and vim of untried youth. It is when issuing thus in hordes from the water and seen by the ignorant, that they gain the reputation of being rained down, when they really were rained up. It is quite impossible for a beginner to detect the difference between the toad and the frog tadpole; usually those of the toads are black, while those of the frogs are otherwise colored, though this is not an invariable distinction. The best way to distinguish the two is to get the eggs and develop the two families separately.

The general color of the common American toad is extremely variable. It may be yellowish-brown, with spots of lighter color, and with reddish or yellow warts. There are likely to be four irregular spots of dark color along each side of the middle of the back, and the under parts are light colored, often somewhat spotted. The throat of the male toad is black and he is not so bright in color as is the female. The warts upon the back are glands, which secrete a substance disagreeable for the animal seeking toad dinners. This is especially true of the glands in the elongated swelling or wart, above and just back of the ear, which is called the parotid gland; these give forth a milky, poisonous substance when the toad is seized by an enemy, although the snakes do not seem to mind it. Some people have an idea that the toad is slimy, but this is not true; the skin is perfectly dry. The toad feels cold to the hand because it is a cold-blooded animal, which means an animal with blood the temperature of the surrounding atmosphere; while the blood of the warm-blooded animal, has a temperature of its own, which it maintains whether the surrounding air is cold or hot.

The toad’s face is well worth study; its eyes are elevated and very pretty, the pupil being oval and the surrounding iris shining like gold. The toad winks in a wholesale fashion, the eyes being pulled down into the head; the eyes are provided with nictitating lids, which rise from below, and are similar to those found in birds. When a toad is sleeping, its eyes do not bulge but are drawn in, so as to lie even with the surface of the head. The two tiny nostrils are black and are easily seen; the ear is a flat, oval spot behind the eye and a little lower down; in the common species it is not quite so large as the eye; this is really the ear-drum, since there is no external ear like ours. The toad’s mouth is wide and its jaws are horny; it does not need teeth since it swallows its prey whole.

The toad is a jumper, as may be seen from its long, strong hind legs, the feet of which are also long and strong and armed with five toes that are somewhat webbed. The “arms” are shorter and there are four “fingers” to each “hand;” when the toad is resting, its front feet toe-in, in a comical fashion. If a toad is removed from an earth or moss garden, and put into a white wash-bowl, in a few hours it will change to a lighter hue, and vice versa. This is part of its protective color, making it inconspicuous to the eyes of its enemy. It prefers to live in cool, damp places, beneath sidewalks or piazzas, etc., and its warty upper surface resembles the surrounding earth. If it is disturbed, it will seek to escape by long leaps and acts frightened; but if very much frightened, it flattens out on the ground, and looks so nearly like a clod of earth that it may escape even the keen eyes of its pursuer. When seized by the enemy, it will sometimes “play possum,” acting as if it were dead; but when actually in the mouth of the foe, it emits terrified and heart-rending cries.

The toad’s tongue is attached to the lower jaw, at the front edge of the mouth; it can thus be thrust far out, and since it secretes a sticky substance over its surface, any insects which it touches adhere, and are drawn back into the mouth and swallowed. It takes a quick eye to see this tongue fly out and make its catch. The tadpole feeds mostly upon vegetable matter, but the toad lives entirely upon small animals, usually insects; it is not particular as to what kind of insects; but because of the situations which it haunts, it usually feeds upon those which are injurious to grass and plants. Indeed, the toad is really the friend of the gardener and farmer, and has been most ungratefully treated by those whom it has befriended. If you doubt that a toad is an animal of judgment, watch it when it finds an earthworm and set your doubts at rest! It will walk around the squirming worm, until it can seize it by the head, apparently knowing well that the horny hooks extending backward from the segments of the worm, are likely to rasp the throat if swallowed the wrong way. If the worm prove a too large mouthful, the toad promptly uses its hands in an amusing fashion to stuff the wriggling morsel down its throat. When swallowing a large mouthful, it closes its eyes; but whether this aids the process, or is merely an expression of bliss, we have not determined. The toad never drinks by taking in water through the mouth, but absorbs it through the skin; when it wishes to drink, it stretches itself out in shallow water and thus satisfies its thirst; it will waste away and die in a short time, if kept in a dry atmosphere.

The toad burrows in the earth by a method of its own, hard to describe. It kicks backward with its strong hind legs, and in some mysterious way, the earth soon covers all excepting its head; then, if an enemy comes along, back goes the head, the earth caves in around it, and where is your toad! It remains in its burrow or hiding place usually during the day, and comes out at night to feed. This habit is an advantage, because snakes are then safely at home and, too, there are many more insects to be found at night. The sagacious toads have discovered that the vicinity of street lights is swarming with insects, and there they gather in numbers. In winter they burrow deeply in the ground and go to sleep, remaining dormant until the warmth of spring awakens them; then, they come out, and the mother toads seek their native ponds there to lay eggs for the coming generation. They are excellent swimmers; when swimming rapidly, the front legs are laid backward along the sides of the body, so as to offer no resistance to the water; but when moving slowly, the front legs are used for balancing and for keeping afloat.

The song of the toad is a pleasant, crooning sound, a sort of gutteral trill; it is made when the throat is puffed out almost globular, thus forming a vocal sac; the sound is made by the air drawn in at the nostrils and passed back and forth from the lungs to the mouth over the vocal chords, the puffed-out throat acting as a resonator.

The toad has no ribs by which to inflate the chest, and thus draw air into the lungs, as we do when we breathe; it is obliged to swallow the air instead and thus force it into the lungs. This movement is shown in the constant pulsation, in and out, of the membrane of the throat.

As the toad grows, it sheds its horny skin, which it swallows; as this process is usually done strictly in private, the ordinary observer sees it but seldom. One of the toad’s nice common qualities is its enjoyment in having its back scratched gently.

The toad has many enemies; chief among these is the snake and in only a lesser degree, crows and also birds of prey.

Reference—The Frog Book, Dickerson; Familiar Life in Field and Forest, Mathews; The Usefulness of the American Toad, U. S. Dept. Agr., Farmers Bulletin, No. 196.