. Beginners' Zoology . e? Is the symmetry of the fish bilateralor radial? The body of the fish maybe divided into three regions—the head, the trunk, and the tail. The trunk begins with theforemost scales; the tail is said to begin at the vent, oranus. Which regions bear appendages? Is the headmovable independently of the trunk, or do they movetogether ? State the advantage or the disadvantage in the body depressed (flattened vertically) or compressed no BEGINNERS ZOOLOGY (flattened laterally)? Do both forms occur among fishes?^(See figures on pages 123, 124.) How is the shape of the bo
. Beginners' Zoology . e? Is the symmetry of the fish bilateralor radial? The body of the fish maybe divided into three regions—the head, the trunk, and the tail. The trunk begins with theforemost scales; the tail is said to begin at the vent, oranus. Which regions bear appendages? Is the headmovable independently of the trunk, or do they movetogether ? State the advantage or the disadvantage in the body depressed (flattened vertically) or compressed no BEGINNERS ZOOLOGY (flattened laterally)? Do both forms occur among fishes?^(See figures on pages 123, 124.) How is the shape of the body advantageous for tnove-ment ? Can a fish turn more readily from side to side, orup and down ? Why ? Is the head wedge-shaped or coni-cal? Are the jaws flattened laterally or vertically ? Thefish swims in the water, the bird swims in the air. Accountfor the differences in the shape of their bodies. Is the coveri7ig of the body like the covering of any ani-mal yet studied ? The scales are attached in little pockets,. Fig. 209.— White Perch {Morone Americana). or folds, in the skin. Observe the shape and size of scaleson difierent parts of the body. What parts of the fish arewithout scales ? Examine a single scale; what is itsshape ? Do you see concentric lines of growth on a scale ?Sketch a few of the scales to .show their is the use of scales ? Why are no scales needed onthe head ? How much of each scale is hidden ? Is therea film over the scale ? Are the colours in the scale oron it ? The Fins.—Are the movements of the fish active orsluggish ? Can it remain stationary without using its fins ? FISHES III Can it move backward ? How are the fins set ir. motion ?What is the colour of the flesh, or muscles, of a fish? Countthe fins. How many are in pairs ? (Fig. 209.) How manyare vertical 1 How many are on the side} How manyare on the middle line? Are the paired or the unpaired finsmore effective in balancing the fish ? In turning it fromside to side ? In r
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