What kind of animal is the earthworm?
It is helpful to know the main classifications of the animal kingdom. Then., when your curiosity leads you to look up some fascinating fellow in a reference book, you can read a lot more into the words. The animals in each group have certain features in common. A member of the order Primates, pronounced pry may tse, with the accent i the middle, is a monkey type animal. The scientific name of the group also gives a clue. The classifications are graded from the most simple to the most complex and Primates, related to the word prime, means that these animals are at the top of the list.
The earthworm is not the simplest of all animals, nor is he the most highly developed, Sincs he has no backbone, no bones of any kind, he is rated as an invertebrate animal. But his rating is much higher than the one celled protozoa, even higher than the sponges and the jellyfish. However, he is not so highly developed as the insects. But, strange to say, he can do some things better than the highly developed monkeys and some wonderful things which they even cannot do at all,,
Zoologists rate Pinky between the hookworms and the lobsters. His phylum is Annelida, a name coined from older words meaning little rings. His little rings, of course, are the round segments which circle his body from tip to tip. Each segment is a round band of muscle with four almost invisible bristles on the underside. Another set of muscles runs lengthwise of the wormy body. When he travels, the earthworm grips the soil with his bristles. The long muscles and the ringed muscles relax and contract by turns.
The soft, elastic skin is just an outer tube. The important organs of the earthworm's body are in side an inner tube.
He has blood vessels, a nervous system, digestive organs and a heart of sorts, This inner tube of the earthworm makes him just about the most valuable farmer in the world. In an acre of good soil, there are about one million earthworms and in ten years this busy crew turns over about two inches of topsoil.
This trick is most valuable to plant life, The soil is loosened to let air and moisture reach the roots. Decaying debris on the top is taken below where its rich chemicals can feed the plants. The worm does this job by eating dirt. His little gizzard digests the fragments of food and the useless soil Is deposited in a curly little pile called a casting, This dirt is brought from below and left on the surface as Mr. Pinky eats his dinner and digs his burrow in the same economical operation.
The great scientist, Charles Darwin, was amazed at the valuable talents of the humble earthworm. He called the little annelid Nature’s plowman. In North America, Mr. Pinky has about 90 different cousins. Throughout the world there are some 7,000 different annelids and most of them live in fresh or salt water. The giant of the phylum Annelida is an Australian worm ten feet long.