INTRODUCTION. 63 
comparatively little value. To this may be added, 
that the caterpillars are often difficult to discover, 
owing to the nature of their haunts, many of them 
living in the interior of trees, within the substance 
of herbaceous vegetables, in fruits, &c. But the 
want of this knowledge, from whatsoever causes it 
may arise, has hitherto been a principal cause, and 
will probably long continue to be so, of preventing 
a natural arrangement of this tribe being effected ; 
and the observation of Latreille will in all likelihood 
long continue to be applicable, — " Nepotes nostri 
methodum optimam soli conficient." 
Before referring to a few of the principal me- 
thods in which it has been proposed to arrange the 
nocturnal Lepidoptera, it will be of advantage to 
take a slight glance at some of those authors who 
have contributed most to extend our knowledge of 
exotic species, and from whose works the materials 
must be principally derived to form the basis of 
these arrangements. 
The works relating to the nocturnal Lepidoptera 
of Europe are numerous and valuable. One of the 
most extensive and useful is the " Die Schmetter- 
ling von Europa," by Ochsenheimer and Treitschke, 
in 14 vols. 8vo. Leipzig, 1807 — 34. Godart has 
described the species indigenous to France ; Dupon- 
chel has continued the work, and given an Icono- 
graphy of the Caterpillars (Paris, 1832, 8vo.). 
Hubner, Dennis and Schiffermiiller, Boisduval, and 
many others, have likewise made valuable contri- 
butions to the subject, in reference to its relations 
