Encyclopaedia of Amphibia (Amphibia of Past and Present) e-bog

The amphibians have sprung up from fish-like ancestor and thai in turn given rise lo reptile*. Thus, amphibian consequently hold & very important intermediate position. The term /lwpJiil>iii was coined by Linnaeus although he kept both, the amphibians as well as some reptiles in this particular class- Later on naturalists and taxonomisls put the amphibians particularly in this class, although the characteristic (ealures of the old amphibian* and those of recent are little more different. The main characteristics of Amphibians are: They may be. aquatic, terrestrial or both; these are cold-blooded (polkilothermous) animals. Their body temperature is variable and most of Ihem undergo hibernation during winter. Some undergo aestivation during summer; the shape ol body ts variable, it may be depressed or cylindrical and divisible into head, neck, trunk and tail or into head and trunk. The skin is thin, moist, glandular and devoid of exoskcleton. There is a pair of nostrils, which open into the buccal cavity. They are provided with valves to exclude water. The teeth are alike {homodont), acrodonl and polyphyottoni: Endoskeleton is largely bony or ossified. Skill W dkmidylic Le. possesses two occipital condyles for the attachment to (he vertebral column. Eyes are provided with movable lids and tear glands to clean and protect them in air. [train has smooth cerebral hemispheres and the cerebellum is poorly developed. Fertilization is generally external, sometimes internal, figgs are inesolecithal and arc covered with gelatinous covering. They are laid in water. This encyclopaedic work in three volumes is designed to preswt entire vital information on Amphibia. Profusely illustrated in the light of latest researches, this Work is a dependable reference Work for smdrnt*. teachers and -, in the discipline.