X PREFACE. 



more immediate objects. He finds his pleasure in the con- 

 templation of their novel forms, in the examination of those cha- 

 racters which distinguish them as species, in the quest of their 

 mutual affinities, their relations and analogies with other beings, 

 the order in which Creative Wisdom may seem to have called 

 them into existence, their habits, economy and uses ; — and in 

 all these things he is ever watchful to find a " moral compli- 

 ment" that the pursuit to which his taste and constitution of mind 

 has led him may be neither uninfluential nor virtueless on his 

 heart. 



The plates and wood-cuts which illustrate the volume are, 

 with few exceptions, original, — engraved from drawings made 

 for it by Mrs Johnston, who is herself the engraver of fourteen 

 of them. The naturalist who may have attempted similar il- 

 lustrations will appreciate the labour, perseverance and skill 

 which has been bestowed upon them, and will not harshly 

 censure any errors of detail which a minute criticism may dis- 

 cover. As I could not have undertaken this history without 

 her assistance, I may crave, from any one who shall find a merit 

 in it, the ascription of that merit to my colleague. 



Behwick-upon- Tweed, 

 August 15, 18.38. 



