OBSERVATIONS SOME INTERESTING PHENOMENA IN ANIMAL PHYSIOLOGY - 1814 - PREFACE - THE following Observations are chiefly extracted from a journal of incidents in natural history, kept as occasion offered, during several successive years. Many interruptions opposed their progress the concurrence of circumstances indispensible for connected detail were frequently wanting experimeilts mere rendered abortive by casualties and hence the imperfections which they now exhibit. Nothing is referred to but what has actually beell witnessed, which is a better means of promoting the pr, ogress of science than resorting to the auxiliary authority of, other naturalists. Dates are given to aid the illustrations, not to claim any priority of observation, were such even worthy of appropriation. Possibly, analogous enquiries have long ago been instituted by those more qualified for the task and, what has appeared obscure in the nature of the animals now brought under consideration, may already be elsewhere satisfactorily explained. The Figures, which, will elucidate the subject where verbal description fails, have invariably been dr.awn from living Planariae in motion, and generally after having fed, as the most ample view of their, organization is then presented. - Naturalists, . who take these- animals indiscriminately. from their native abodes, may therefore find discrepancies, resulting from- a state of abstinence and variations still more conspicuous may appear, from the unequal evolu- .. tion of nascent parts. But experience will speedily inculcate, where, after passing all the successive stages, perfection at length is gained. Nevertheless, the size is somewhat less than life, because Planarire alwaysdecline in a state of confinement. The name of any species distinctly recognized is retained and if. a new one is bestowed on those where this is doubtful, - - it is only to put their idbtity beyond future dispute. It cannot but appear remarkable, that peculiar. difficulty should have been experienced here that a certain genus should be instituted and a number of species, all distinguished by individual characteristics, brought. under it, which scarcely, in a single instance, demonstrate the place to which they belong. Yet this will appear less surprising, when we reflect that the site of an organ, the most important assuredly, .the, mo-uth has hitherto been referred to the anterior extremity in all, instead of the middle of the belly, its- - general position. a Although the Observations which occupy these pages lead to very different conclusions from what such eminent naturalists as Linnzus, Cuvier, and perhaps the learned and indefatigable Muller, have endeavoured to deduce for the purpose of systematic arrangement, names so celebrated ought not to. be mentioned without the utmost deference. Had the genus Plana-. ria engaged their protracted investigation, the- phenomena n6w exposed mould not have remained so long in concealment. The errors which have darkened the beautiful science of Natural History, are principally to be traced to superficial observation and if this be true with regard to the larger animals, how is it to be expected that the smaller have received that scrupulous care and attention, by which alone their habits can be illustrated Scarce deemed worthy to hold a place in existence, they have been obscured by more conspicuous objects, those whose properties it requiredless time and labour to unfold...

ISBN-13: 9781408610077 ISBN-10: 1408610078 Publisher: Dyer Press Publish Date: October 2007 Page Count: 164 Related Categories Books > Science > General