1. Aglossa—Having no tongue.
2. Phaneroglossa—Possessed of a tongue.
The Aglossa are few in number, and belong to southern Africa and tropical America, where the group is represented by the famous Surinam toad, whose eggs are fixed in separate pits or "pouches" in the spongy skin of the mother's back, where they are placed as fast as laid, by aid of the male.
The Phaneroglossa contains several families, the first of which, Discoglossidæ, is characterized by the round, nonprotrusible tongue, and includes species of toads belonging mainly to the Mediterranean region, two of which are familiar to most readers of natural histories.
It may be well to say at this point that the terms "toad" and "frog" do not express scientific distinctions, although generally applied by naturalists to the first three families of the list, and especially to the Bufonidæ; but mark the facts of popular observation that the members of these families are more terrestrial than the members of the families that follow them, and that they have rough warty skins in place of smooth and shiny ones; but many exceptions confuse both the classification and the use of the words—as, for example, in the case of the hylas, which you may call either "tree frogs" or "tree toads," according to your liking.
The two species mentioned above are the "unke," or firebellied toad of Germany, which when alarmed displays its scarlet underparts by a peculiar attitude calculated to surprise and frighten away an enemy. The other is the "midwife toad," most common in Spain and Portugal.
The spade-foot toads (Pelobatidæ) are a strangely distributed family inhabiting the western United States, Mexico, eastern Europe, and the Indo-Malayan region. Their special characteristic is the fact that the inner tarsal tubercle is large and is transformed into a shovel, which is covered with a hard, sharp-edged, horny sheath. Having this excellent tool these small and noisy toads rapidly excavate deep holes in the soil, preferring sand, and lie hidden during the day, but come forth at night to hunt. They resort to water only for a week or so of egg-laying in the spring, and remain unknown to most persons in whose neighborhood they are really numerous. Our common American one (Scaphiophus solitarius) is about two inches long, and brown above with darker patches.
This brings us to the typical toads, Bufonidæ, represented in all parts of the world except certain islands. A hundred pages might be filled with interesting accounts of the manners and customs of the hundred or so species, many very different from those familiar to us.
All breed in water, resorting to ponds and pools in the early spring. Where many broods have hatched the young can be met with in myriads, the ground literally swarming with them; and as they are naturally stirred up by a sudden warm rain, perhaps after a drought, people will occasionally affirm as an observed and well-ascertained fact that "it has rained toads"—something that never occurs except in the very rare cases when a cyclone has scooped the water and everything in it out of a pond and scattered it abroad.
Most of these young, migrating toads disappear as food for birds, snakes, etc., or die of disease. The food of young and old consists of insects, worms, snails, and the like; and it is an easy thing to tame toads and have much amusement in watching them at work in the early evening, for they are crepuscular in habits; and the wise gardener will see that they are not disturbed in their beneficial service of catching and devouring insect pests, unless they are so numerous as to be a nuisance.