PREFACE TO SECOND EDITION. 



The call for a new issue of this work within little more 

 than six months after the appearance of the last, is a 

 very gratifying proof that, in spite of its defects, the 

 work supplies a recognised want, and that the Author 

 has to some extent succeeded in the objects aimed at. 



With regard to the present edition, the Author need 

 only say that the entire work has been carefully revised, 

 and all the more striking discoveries of recent date have 

 been noticed, whilst some errors have been corrected. 

 Considerable additions have also been made, especially 

 in the department of Vertebrate Zoology. The Author, 

 however, would ask his readers to remember that the 

 compass of the work will not admit of the introduction 

 of many details, which must be sought for in other more 

 extensive treatises, and that only the more important 

 facts of Natural History should be looked for in a \york 

 of such limited size. 



Lastly, no change has been made in the plan of classi- 

 fication adopted in the former editions of this work, and 

 based essentially upon the views put forth by Professor 

 Huxley. It is true that this classification is a modern 



