Transcriber’s notes: In this transcription, paired underscores denote _italicised text_, paired asterisks denote *bold text* and a ^ (caret) indicates that the following bracketed character was superscripted in the original text. Footnotes have been positioned below the relevant paragraphs. A small number of errors have been corrected silently, including the following: Amæbæ —> Amœbæ continuea —> continued translalations —> translations Harvar —> Harvard ST. —> St. missing word ‘in’ inserted redundant comma deleted The following misplaced section of text has been correctly positioned: disowned. But these are not its best features: its sustained power of reasoning, its wide sweep of observation and reflection, its elevated ethical and social tone, stamp it as a work of high excellence, and as such we cordially recommend it to our readers.”--Saturday Review. Inconsistently labelled passages of text are as in the original, e.g. a b c d; a b c e; _ b c e; A title has been added to the original featureless book cover. _In the Press, in Two Volumes, Crown 8vo., with numerous Illustrations_, THE BEGINNINGS OF LIFE. BY THE SAME AUTHOR. London and New York: MACMILLAN AND CO. [Illustration: LOWEST ORGANISMS. Fig. 1.--The simplest forms of Life--_Bacteria_, _Torulæ_, _&c._ Fig. 2.--_Bacteria_, _Vibriones_, and _Leptothrix_ filaments. (× 800 diameters.)] THE MODES OF ORIGIN OF LOWEST ORGANISMS: INCLUDING A DISCUSSION OF THE EXPERIMENTS OF M. PASTEUR, AND A REPLY TO SOME STATEMENTS BY PROFESSORS HUXLEY AND TYNDALL. By H. CHARLTON BASTIAN, M.A., M.D., F.R.S., FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS; PROFESSOR OF PATHOLOGICAL ANATOMY IN UNIVERSITY COLLEGE, LONDON; ASSISTANT PHYSICIAN TO UNIVERSITY COLLEGE HOSPITAL, AND TO THE NATIONAL HOSPITAL FOR THE EPILEPTIC AND PARALYSED. London and New York: MACMILLAN AND CO. 1871. [_All rights reserved._]