. Animate creation : popular edition of "Our living world" : a natural history. Zoology; Zoology. ARTHROPODA. Rp]ATURES that compose this great Branch of the Animal Kingdom were regurrfetl by Cuvier as articulated animals having a symmetrical body, in that both sides were equal. One of his four great Divisions embraced these forms, under the title Articulata. The bodies of these animals are characterized by a peculiar feature, tlie series of rings, of which the earth-worm is a simple example. The circulating system is represented just under the back by a long vessel, the heart, conne
. Animate creation : popular edition of "Our living world" : a natural history. Zoology; Zoology. ARTHROPODA. Rp]ATURES that compose this great Branch of the Animal Kingdom were regurrfetl by Cuvier as articulated animals having a symmetrical body, in that both sides were equal. One of his four great Divisions embraced these forms, under the title Articulata. The bodies of these animals are characterized by a peculiar feature, tlie series of rings, of which the earth-worm is a simple example. The circulating system is represented just under the back by a long vessel, the heart, connecting with vessels that propel the blood over the system, and return it to the gills, or lungs. The stomach and intestine lie in the median line of the body. The nervous system has ganglia, or enlargements of the nervous cords. The Arthropoda have certain features in common: bi-lateral symmetry, one side being like the other ; rings, or articulating parts, segments, ari-anged one upon another, each ring— theoretically—bearing a pair of limbs, which are also Jointed. Tlie blood is usually colorless, yet in some instances yellowish, or red, or purple. The globules of the ])iood, however, are not colored, the coloring matter being held in the fluid itself. The alimentary canal is usually nearly straight. The eyes are usually confined in the head. Authors have formerly divided the Arthropoda into two classes, the Insects and Crusta- ceans ; but the places of some examples are so obscure they are held somewhat in reserve. The Horseshoe Crabs and Trilobites, Water-Bears, Sea-Spiders, and LinguatuUna are now resting between the two classes, Insecta and Crustacea, where authors are inclined to believe they will ultimately find a permanent place. INSECTS; INSECTA. The Insects afford the first examples of the Articulata, i. e., the jointed animals without vertebra). Their bodies are composed of a series of rings, and they are separated into at least two and mostly three portions, the
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Keywords: ., bookauthorbr, bookcentury1800, bookdecade1890, booksubjectzoology
