VI PREFACE. 



the animal kingdom. "We may go farther than this, 

 and say, that if we had been ready to take hints from 

 the structures which we find in animals, and those 

 which are built up by them, many improvements in 

 the arts might have advanced much more rapidly 

 than they have done. For example, in the construc- 

 tion of optical instruments, a difficulty which Sir Isaac 

 Newton thought never could be remedied, chromatic 

 aberration, might have been remedied long before it 

 was if that perfect optical instrument made by the 

 Creator, the Eye, had been properly examined in re- 

 lation to this point. So, too, paper might long ago 

 have been made from wood, if the habits of that first 

 paper-maker, the wasp, had been observed. 



Another reason for making this study prominent is, 

 that its connection with other studies is such that it 

 contributes greatly to their interest and resources. 

 This is true, for example, of Geography. It adds 

 vastly to the interest of this study to have the pupil 

 know familiarly how the various tribes of animals are 

 distributed over the earth, and what relation this dis- 

 tribution has to climate, situation, etc. The connec- 

 tion between Zoology and Geology is of the most in- 

 timate character, as the pupil will see in the course of 

 his study of this book. Then, too. Chemistry and 

 Natural Philosophy, especially the latter, have many 

 of their best illustrations in the composition and struc- 

 ture of animals, so that Zoology, with its relations to 

 Physiology properly developed, will offer no incon- 

 siderable additions to the interest of the two depart- 

 ments of science above named. 



But the grand practical benefit to be derived from 

 the study of Natural History, or, indeed, any of the 



