vi PREFACE. 



solitary sleigh drive over frozen lakes in North Ame- 

 rica ; some in the great forests of Central and South 

 America ; some on the wide ocean, with the firmament 

 above and below blending together on the horizon; 

 and some, again, in the bowels of the earth, seeking 

 for the mine's hidden riches. The thoughts are those 

 of a lifetime compressed into this little book ; and, 

 like the genii of the Arabian tale, imprisoned in an 

 urn, they may, when it is opened, grow and magnify, 

 or, on the contrary, be kicked back into the sea of 

 oblivion. 



This much is necessary; not to disarm criticism, 

 but to excuse myself to those authors whose labours 

 on some of the subjects I have treated of may not have 

 been mentioned. I have, during my various sojourns 

 in England, worked hard to read up the literature of 

 the various questions discussed, but I know there 

 must be man} 7 oversights and omissions in referring to 

 what others have done ; especially with regard to 

 continental writers, for I know no language but my 

 mother-tongue, and their works, excepting where I 

 have had access to translations, have been sealed 

 books to me. 



I am indebted to Mr. H. W. Bates for much assist- 

 ance, and especially for undertaking the superin- 

 tendence of these sheets in their passage through the 

 press ; to Mr. W. C. Hewitsoii, of Oatlands Park, I am 

 under many obligations for taking charge of my ento- 

 mological collections, for naming many of my butter- 

 flies, and for access to his magnificent collection of 



