genus, of a species. Where a name occurs on many pages of Mr. Jackson's work, our reference is to the index of that work.
Although our information is largely derived from printed sources, it is also the result of private letters of inquiry; and where we differ from the various published biographies, it by no means indicates that we have not consulted them, or that we are necessarily wrong.
Most of our abbreviations are so generally used as to require no explanation, though we are conscious that, in this and in other points, we have not always followed a uniform usage. PI. for plants, Fl. for Flora, and Herb, for Herbarium need no glossary.
The work originated in the want felt by the compilers of some reference-list of byegone workers in Botany. After several years of preparation, we thought it sufficiently advanced for publication at the beginning of 1888, and from that date down to the end of 1891 it appeared almost continuously month by month in the Journal of Botany (vols, xxvi.-xxix.). During its appearance we received many gratifying letters of approval and encouragement from botanists of eminence in all parts of the world, and much valuable supplementary information. No one can be more fully aware than we are of the numerous imperfections in our records. Such a work must of necessity contain errors both of commission and of omission, and few who consult it can form an adequate opinion of the labour involved in collecting information which, when set down, may appear of the most meagre character. Our plan somewhat extended itself as the serial issue of our work proceeded, and this, coupled with such corrections as reached us, has necessitated a more complete re-editing of the entire Index than we anticipated. This has occupied us for more than a year, and enabled us to bring down our record to the end of 1892. The extent of this revision may be gauged from the facts that, whereas the issue in the Journal of Botany comprised 1,619 names, occupying 148 pages, an average of over ten names to the page, in its present form our little book contains 1,825 names, and occupies 188 pages, an average of less than ten names to the page.
The following is a list, with abbreviated titles, of the chief sources of information which are quoted by some abbreviation. It probably does not include a tithe of the works actually consulted, many of which are referred to under titles so little shortened as to require no explanation.
