. Elementary zoology. Zoology. BRANCH ARTHROPOD A; CLASS INSECT A : THE INSECTS 181 not be so miscalled. These last belong to the branch Arthropoda but to other classes than the class Insecta. While insects are found living under most diverse condi- tions on land, that is, on the ground, in the leaves, fruits and stems of plants, in the trunks of trees or in dead wood, in the soil, in decaying animal or plant matter, as parasites on or in other animals, and in all fresh-water ponds and streams, they do not live in ocean water. A few species live habitually on the surface of the ocean, and a fe
. Elementary zoology. Zoology. BRANCH ARTHROPOD A; CLASS INSECT A : THE INSECTS 181 not be so miscalled. These last belong to the branch Arthropoda but to other classes than the class Insecta. While insects are found living under most diverse condi- tions on land, that is, on the ground, in the leaves, fruits and stems of plants, in the trunks of trees or in dead wood, in the soil, in decaying animal or plant matter, as parasites on or in other animals, and in all fresh-water ponds and streams, they do not live in ocean water. A few species live habitually on the surface of the ocean, and a few other forms are found habitually on the water- drenched rocks and seaweeds between tide lines. The varied habits of insects, their economic relations with man. the beauty and grace of many of them, and the readiness with which they may be collected, reared and studied, renders them unusually fit animals for the special attention of beginning students of zoology. Body form and structure.—The segments composing the body of an insect are grouped to form three body-regions, the head, thorax, and abdo- men. The head of an adult insect appears to be a single segment or body-ring, but in reality it is composed of several segments, probably seven, completely fused. The head bears the eyes, antennae and the mouth- parts. The thorax is made up of three seg- ments, each segment bearing a pair of legs. From the dorsal side of the hinder two thoracic segments. Fig. 45.—A wingless insect; the American spring-tail, Lepidocyrtas americanus, common in dwelling-houses. The short line at the right indicates the natural size. (From Marlatt.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Kellogg, Vernon L. (Vernon Lyman), 1867-1937. New York : H. Holt and company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1902
