PREFACE. 



Isr bringing out a Text-book of Natural History, intended 

 mainly for the use of schools, there are a few remarks which 

 it may be as well to make by way of preface, if only to ex- 

 plain the principles upon which the work has been written. 



In the first place, more space has been devoted, compara- 

 tively speaking, to the Invertebrate Animals than has usually 

 been the case in introductory works, upon the belief that any 

 practical Zoological work likely to be undertaken by young 

 students will certainly be in connection with these rather 

 than with the Vertebrate Animals. 



Secondly, the Author has devoted considerable space to a 

 discussion of the principles of Zoological classification, be- 

 lieving that it is of paramount importance that the student 

 should have a clear idea of the principles upon which the 

 Animal Kingdom has been systematically divided. At the 

 same time, the introductory portion of the work is more 

 especially intended for the teacher ; and there is much in it 

 that the learner may perhaps hardly understand till he has 

 arrived at some clear idea of Natural History as a whole. 



Thirdly, while the Author trusts that the style of the 

 work wiU be found clear and intelligible, he does not believe 

 in the existence of any royal road to learning in Natural 

 History, any more than in any other department of human 

 knowledge. If Natural History is ever to be taught in 



