Produced by Thiers Halliwell, Chris Curnow and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) The text of this e-book has been preserved in its original form apart from correction of several typographic errors: (rog → frog, arrranged → arranged, downword → downward, and → of (in journal title), developes → develops). Inconsistent use of accents and hyphenation, and inconsistent spelling, e.g. referable/referrible, has not been altered. Several redundant parentheses have been deleted. Paragraphs of quoted text on pp. 17–19 are incomplete and/or paraphrased (compared with the original sourc…
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