Vlll 
PREFACE. 
The first and second chapters, having been rewrit¬ 
ten with considerable care, are now reprinted under 
a title appropriate to their object. In the course of 
preparing them for publication, they seemed to expand 
beyond the ordinary limits of chapters, and have 
therefore been further subdivided, making eleven 
instead of two. I trust this will be found a convenient 
arrangement. 
The diagrams employed in the first edition, having 
reference exclusively to Entomology, are omitted. 
A map of the animal kingdom is added at the end. 
In this man is supposed the centre, and departure 
from his characters is expressed by a series of con¬ 
centric circles. 
London , March , 1843. 
