Beginners' zoology . lves of a musselis the hinge ligament in a stretched condition ? How doesthe shape of the mussels gills insure that the water cur-rent and the blood current are brought in close contact? The three main classes of molluscs are: the pelecypoda(hatchet-footed); gastropoda (stomach-footed); and cepha-lopoda (head-footed). Give an example of each class. Comparison of Mollusks Shell Head Body Foot Gills Eyes Mussel Snail Sqcid Comparative Review. —(To occupy an entirt<page in notebook.) Grass-hopper SpmER CRA\rt5H Centipede Mossel Bilateral or radiate Appendages for lo-comoti
Beginners' zoology . lves of a musselis the hinge ligament in a stretched condition ? How doesthe shape of the mussels gills insure that the water cur-rent and the blood current are brought in close contact? The three main classes of molluscs are: the pelecypoda(hatchet-footed); gastropoda (stomach-footed); and cepha-lopoda (head-footed). Give an example of each class. Comparison of Mollusks Shell Head Body Foot Gills Eyes Mussel Snail Sqcid Comparative Review. —(To occupy an entirt<page in notebook.) Grass-hopper SpmER CRA\rt5H Centipede Mossel Bilateral or radiate Appendages for lo-comotion Names of divisionsof body Organs and methodof breathing Locomotion CHAPTER X FISHES Thecom Suggestions.^ The behaviour of a live fish in clear water, preferably in a glass vessel or an aquarium, should be A skeleton may be prepared by placing a fish in the reach of ants. Skeletons of animals placed on ant beds are cleaned very thoroughly. study of the perch, that follows, will apply to almost any other mon Movements and External Features. — What is the gen-eral shape of tJie body of a fish ? How does the dorsal, orupper, region differ in form from the ventral ? Is there anarrow part or neck where the head joins the trunk}Where is the body What is the ratio betweenthe length and the height? (Fig. 209.) Are the right andthe left sides alike? Is the symmetry of the fish bilateralor radial? The hody 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 109 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 move-ment ? Can a fish tu
Size: 1938px × 1289px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1921
