SOME COMMON ANIMAL FORMS
Brief lessons should be given on some of the lower members of the animal kingdom, for the purpose of broadening the interests of the pupils. The following are suggested as types: snail, spider, freshwater mussel (clam), crayfish (crab), centiped, milliped, salamander, and wood-louse.
These are common animal forms, most of which are frequently seen by the pupils, but seldom are their interesting life habits or their places in the animal kingdom recognized. The salamander is to many pupils a lizard of the most poisonous kind; centipeds and millipeds are worms, and they do not recognize that the clam is an animal with sensibilities and instincts.
REFERENCES
Kellogg: Elementary Zoology
Silcox and Stevenson: Modern Nature Study
CENTIPEDS AND MILLIPEDS
Under stones and sticks in moist soil are to be found two worm-like forms, both having many legs.
One of these animals is flat, about an inch long, brown in colour, and provided with a pair of long feelers. On each division of the body is a single pair of legs. This is the centiped. The other animal is more cylindrical in shape and has two pairs of legs on each division of the body. Its colour is a darker brown than that of the centiped, and it has a habit of coiling into a spiral shape, when disturbed, so that the soft under surface is concealed. This is the milliped. Both of these animals are quite harmless and feed on decaying vegetable matter. They stand midway between worms and insects in forms and habits.
A brief observation lesson on each animal, involving their movements and the structural features named above, will enable the pupils to identify them and to appreciate their position in the animal kingdom.
SALAMANDERS, OR NEWTS
Some forms of these are found in water, as in streams, ponds, and ditches, while other forms are found on land, where they hide under stones and sticks. They are commonly mistaken for lizards, which they closely resemble in shape; but the two animals may be distinguished by the fact that the surface of the body of a salamander is smooth, while that of a lizard is covered with scales.
The small red or copper-coloured newts are the most common in Ontario and are frequently found on roads after heavy rains. The tiger salamanders are larger than the red newts and are marked with orange and black spots, hence the name "tiger". Many people believe this species to be especially venomous, while in reality it is quite harmless and, like the other salamanders, is useful for destroying insects and small snails, which form the greater part of its food.
To the teacher.—The superstition of the salamander's power to extinguish a fire into which it is thrown still exists. The early life of the salamander is spent in water, the young form being very much like a tadpole. The salamanders are close relatives of the frogs and toads and may be kept in a jar or vivarium in wet moss or grass. The pupils should learn to recognize the animals and should be instructed as to their habits.
SPIDERS
Problems in observation.—In how many places can you find spiders' webs? How many forms of spiders' webs can you find? Are the many webs that are found on the meadow grass in the dewy mornings the homes of spiders? If so, describe where the spiders live. (At the bottom of tunnels that run into the ground.)
What uses do spiders make of their webs? (Trapping prey, supporting egg cases, protection, and means of moving, as in the case of cobweb spiders.)
Drop a fly upon a spider's web and observe the action of the spider. Search under the webs of spiders in attics and sheds and learn, from the skeletons found there, what the spider feeds upon. It will be found that flies, beetles, and other spiders are killed by this monster.
Watch a spider spinning its web and find out what parts of the body are used in this work. It will be seen that the threads are produced from little tubes at the rear end of the animal and are placed and fastened by means of the feet.
Examine, by the aid of a hand lens, the feet and head of the spider. Note the "brushes and combs" on the former. Note, on the latter, the four, six, or eight eyes (the number and arrangement vary), and the short poison claws at the front of the head. How are the poison claws adapted for seizing and piercing? Note the sharp hooks at the lower ends.