PREFACE TO THE PRESENT EDITION. 



AN interval of twelve years having elapsed since the appearance of 

 the first edition of " Carpenter's Zoology," it was found necessary, upon 

 its republication, to submit the whole work to a careful revision, in 

 order to render it an accurate representation of the present state of 

 Zoological Science. Dr. Carpenter, who would of course be the fittest 

 person to revise his own book, was prevented by his numerous avoca- 

 tions, coupled with the state of his health, from entering upon an un- 

 dertaking which would necessarily require a considerable amount of 

 time and labour for its due performance ; and under these circum- 

 stances the Publisher, with Dr. Carpenter's concurrence, applied to 

 the present Editor to undertake the task. This he has performed to 

 the best of his ability, although, from his being placed in the some- 

 what anomalous position of the Editor of the work of a living Author, 

 it was not without its difficulties. 



In preparing this edition, the Editor has endeavoured to preserve 

 as much as possible of the original work, and also to maintain and 

 follow out the Author's mode of treatment in those parts which re- 

 quired alteration. Changes have been introduced only when they ap- 

 peared to be imperatively called for ; and in some instances, where a 

 difference of opinion still exists in the minds of Zoologists, the original 

 statements of the Author have been retained, even where opposed to 

 the Editor's own views. In the first volume, which treats of the higher 

 Vertebrated Animals, the alterations are comparatively few, and re- 

 late principally to matters of detail ; the most important being the 

 elevation of the Batrachia to the rank of a distinct class. The second 

 volume, however, containing the Fishes and the In vertebra ted Animals, 

 required to be in great part remodelled, in order to give due system- 

 atic effect to the numerous and important discoveries which have been 

 made of late years in the anatomy and history of the lower classes of 

 the animal kingdom. 



W. S. D. 

 London, 9th September, 1857. 



