calls the female in a dull voice, so plaintive that the Romans described it by the words "ololo," or "ololygo." "Truly," says Lacépède, "the accent of love is always mingled with some sweetness." When autumn arrives Frogs cease from their habitual voracity, and no longer eat. To protect themselves from the cold, they bury themselves deeply in the mud: troops of them joining together in the same place. Thus hidden, they pass the winter in a state of torpor; sometimes the cold freezes their bodies without killing them. This state of torpor gives way in the first days of spring. During the month of March, Frogs begin to awake and to move themselves; this is their breeding season. Their race is so prolific that a female can produce from six to twelve hundred eggs annually. These eggs are globular, and are in form a glutinous and transparent spheroid, at the centre of which is a little blackish globule; the eggs float, and form like chaplets on the surface of the water. [Illustration: Fig. 5.--Development of the Tadpole. 1. Egg of the Frog. 2. The Egg fecundated, and surrounded by its visicule. 3. First state of the Tadpole. 4. Appearance of the breathing gills. 5. Their development. 6. Formation of the hind feet. 7. Formation of the fore feet, and decay of the gills. 8. Development of the lungs, and reduction of the tail. 9. The perfect Frog.] All who have observed the small ponds and ditches in the country at this season, will have seen these light and elegant crafts swimming on the surface of the water. After a few days, more or less according to the temperature, the little black spot which is the embryo of the egg, and which has developed itself in the interior of the glairy mass which envelops it, disengages itself and shoots forth into the water: this is the tadpole of the Frog.