Although the text of this volume is substantially as Prof. Brash prepared it, his sudden death whilst it was still in proof prevented him from undertaking the final revision. His task has therefore been completed by Prof. G. J. Romanes who has made the final corrections and a few minor alterations.
The principal change in this new edition is the us of English equivalents of the Paris Nomenclature, although this nomenclature has not been adopted in its entirety and some of the more familiar terms of the Birmingham Revision have been retained. If in such cases there is a marked difference between the two nomenclature, then the equivalent term in the Paris Nomenclature is given (in brackets) in the text. As, however, important differences are few, the majority will be found in the index.