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XVII. 



Elements of Geology. A Text-Book for Colleges and for the General 

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Animal Life, as aifected by the Natural Conditions of Exist- 

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Crayfish : An Introduction to the Study of Zoology. By Professor T. H. 

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Anthropology : An Introduction to the Study of Man and Civilization. 

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XXL 



First Principles. By HERBERT SPENCER. Part I. The Unknowable. 

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The Principles of Biology. By HERBERT SPENCER. 2 vols., 12mo. 

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The Principles of Psychology. By HERBERT SPENCER. 2 vols., 

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The Principles of Sociology. By HERBERT SPENCER. 12mo. 

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The Data of Ethics. By HERBERT SPENCER. Being Part I, Vol. I, 

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Illustrations of Universal Progress. By HERBERT SPENCER. 

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