[page] 216

Either from want of health or from the want of time, Mr. Darwin was unable to prepare an edition of his celebrated Structure and Distribution of Coral Reefs (Smith, Elder), after that of 1874. Since then, however, important researches have been made in connection with the subject, and much has been written about it, not always in favour of the theory originated

by Mr. Darwin and long accepted by many as incontrovertible. In the present handsome reprint of the work no attempt has been made to rewrite it. The text of 1874 is given, and in order to supplement, or where necessary correct, it, Professor T. G. Bonney has added a number of footnotes, valuable as a rule not only aa additions to, or as correction of, the

text, but also for the references they contain. Furthermore, at the end of the volume he has added an Appendix of over fifty pages containing a careful summary of the more important arguments which have appeared both for and against the theory propounded in the volume, since 1874. In Prof. Bonney's opinion the validity of that theory remains unimpaired.