. Essentials of biology presented in problems. Biology. THE VERTEBRATE ANIMALS 291 toad that laid them. This apparent discrepancy is caused by the swelling of the gelatinous substance around them. If possible, count the number of eggs laid by one female.' Toad tadpoles may be distinguished from those of the frog, as they are darker in color, and have a more slender tail and a rela- tively larger body than those of the frog. The metamorphosis occupies only about two months in the vicinity of New York, but varies greatly with the temperature. During the warm weather the tail is absorbed with won
. Essentials of biology presented in problems. Biology. THE VERTEBRATE ANIMALS 291 toad that laid them. This apparent discrepancy is caused by the swelling of the gelatinous substance around them. If possible, count the number of eggs laid by one female.' Toad tadpoles may be distinguished from those of the frog, as they are darker in color, and have a more slender tail and a rela- tively larger body than those of the frog. The metamorphosis occupies only about two months in the vicinity of New York, but varies greatly with the temperature. During the warm weather the tail is absorbed with wonderful rapidity, and the change from a tadpole with no legs to that of the small toad living on land is often accomplished in a few hours. This has given rise to the story that it has rained toads, because during the night thousands of young toads have changed their habitat from the water to the land. The toad is of great economic importance to man because of its diet. No less than eighty-three species of insects, mostly injurious, have been proved to enter into the dietary.^ A toad has been ob- served to snap up one hundred and twenty-eight flies in half an hour. Thus at a low estimate it could easily destroy one hundred insects during a day and do an immense service to the garden during the summer. It has been estimated by Kirkland that a single toad may, on account of the cutworms which it kills, be worth $ each season it lives if the damage done by each cut- worm be estimated at only one cent. Toads also feed upon slugs and other garden pests. Other Amphibians. — The tree frogs (called tree toads) are familiar to us in the early spring as thf " " of the swamjis. They are among the earliest of the frogs to lay their eggs. During mlult life they spend most of their time on the trunks of trees, where thciy receivo im- • See Hodge, Nature Study and Life. ' See Kirkland, Habits, Foorl, and Economic Importance of the American Toad. Bui. 46, Hatch Exper
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbiology, bookyear1911
