PREFACE.

There is no little difficulty in obtaining correct and reliable life histories of most of the greatest naturalists. Many of the men to whom natural history science owes so much, lived extremely retired and uneventful lives; but a few, and as might have been anticipated, the reformers and epoch makers of their respective sciences, have had their most interesting biographies well written. Abstracts of these biographies form a large portion of this book; and the author desires to acknowledge the very copious extracts he has made, from sources which he has recognized in the proper places.