By Helen Mellanby M.D., Ph.D. (auth.)

ISBN-10: 0412213605

ISBN-13: 9780412213601

ISBN-10: 9400958498

ISBN-13: 9789400958494

by Professor L. E. Eastham previously Professor of Zoology within the college of Sheffield such a lot books are written with the purpose of delivering a few specific want, yet few finish with such unmarried goal. Mrs. Mellanby's isn't any exception, for whereas the writer deliberate this paintings to function a consultant to the varsity student, which functionality it fulfils in an admirable approach, it's going to additionally end up of price to the instructor, the college scholar and the beginner naturalist. whereas it can be argued that it's not the functionality of the Uni­ versities to coach traditional historical past within the mostly authorised experience, it's going to constantly be the purpose of Zoologists to understand extra approximately animals, what they're and do, the place they dwell and why they dwell particularly environments. it really is unlucky, in view of the truth that the vast majority of scholars of Zoology input the educating professional­ fession, that the expanding load of guide in morphology, body structure, cytology, genetics, evolution and so forth often makes a private examine of animal existence on the subject of atmosphere virtually most unlikely. The lucky ones stopover at the ocean for a citadel­ night's path in Marine Ecology; the others take posts in faculties with no even this respite and set approximately changing their educational studying to a faculty curriculum. the result's an bad and sometimes slavish imitation of college strategy within the university classification­ room.

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Additional resources for Animal Life in Fresh Water: A Guide to Fresh-Water Invertebrates

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This should be distinguished from the white nodules produced on sticklebacks by the protozoan parasite Glugea, see p. ) For further reference to Trematoda and Cestoda see Fresh-water Biology. H. B. Ward and G. C. Whipple. New York, 2nd. ed. I959. (e) Note on Nemertean Worms The Nemerteans are a small group of animals with some resemblances to the free-living flatworms. They are covered with cilia and have an eversible proboscis. Most species are marine, a few are terrestrial, and two or three are inhabitants of fresh water.

The female has a special exit for the eggs, but in the males the sperms are passed out through the anus. A curious feature of the Nematodes is that the tissues of which their bodies are composed are made up of very few large cells; there are no cilia anywhere, no blood system, and no breathing organs. The eggs are covered by a hard shell. The young Nematode hatches looking very much like an adult except for size. Sometimes they hatch inside the body of the female, but they generally do so after the eggs are laid.

They often glide upside down along the surface of the water, their weight being supported by surface tension. When they are moving they show characteristic shapes which will enable you to know which species you have found after some practice. Turbellarians can be distinguished from leeches by their ANIMAL LIFE IN FRESH WATER having no suckers on the under-surface of the body though they are able to cling to surfaces by pressing their bodies against them, and by the lack of segmentation (compare with leeches on p.

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Animal Life in Fresh Water: A Guide to Fresh-Water Invertebrates by Helen Mellanby M.D., Ph.D. (auth.)


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