Observation.—General shape; division into head, trunk, and limbs; size of head and mouth; position and structure of eyes and ears; difference in the size of the fore and hind limbs, and explanation of this difference by references to the use of the limbs; the hind foot, uses of the web; the glands on the surface of the body and their uses for protection.
Why is a large mouth useful? How are the ears fitted for life in water?
In conclusion, the teacher should make sure that the pupils appreciate the usefulness of the toad and also the beauty represented in its adaptations to its conditions of life. In these particulars the toad is a good illustration of the adage "Handsome is that handsome does".
LIFE HISTORY OF THE TOAD
In early spring look for the toads on the surface of the water in ponds. The music of the toads at this time of year has been described by one naturalist as "one of the sweetest sounds of nature".
The eggs may be found in these ponds at this time. They are attached to long strings of jelly which entwine among grasses and other objects in the ponds. (Frogs' eggs are in masses of jelly, not in strings.) Place some of the eggs in a jar of water and set the jar in the window of the school-room. A great mass of eggs is too much to put in a jar, a few dozen eggs in a pint of water will be more likely to develop. The water in the jar should be changed twice a week.
Observations.—The light and dark areas of the eggs, the dark area gradually increasing in size; the increase in the length of the egg; the gradual change of the dark area into the general shape of a tadpole with head and tail, the first appearance of the gills, the separation from the jelly, the movement by means of the tail, the disappearance of the gills, the growth of the hind legs and, later, of the forelegs, and the disappearance of the tail.
Questions and Observations.—What is the use of the dark colour of the area from which the tadpole is formed?
Explain the uses of the strings of jelly.
Describe how the tadpole swims.