199 
SYSTEMATIC ARRANGEMENT 
OF INSECTS. 
The necessity for an accurate methodical classifica- 
tion by which living objects can he recognised and 
their relations to each other in some measure indicated, 
is even more strongly felt in regard to insects than 
any other department of the animal kingdom. This 
is occasioned by the great amount of their numbers, 
which much exceeds that of any other of the zoolo- 
gical classes. Most authors agree in affirming that 
not fewer than between 80,000 and 100,000 species 
are preserved in collections, and it is computed that 
the species existing in nature is not greatly short of 
400,000. But the very circumstance which makes a 
well digested arrangement so desirable, likewise ren- 
ders it of no easy attainment, owing to the difficulty 
of acquiring the requisite knowledge of such a multi- 
tude of objects. Their structural details are so end- 
lessly diversified, their affinities and analogical rela- 
tions so complex, and their modes of living, in many 
cases, of such difficult determination, that it is scarcely 
to be expected that a system will soon he constructed 
in which each shall find its appropriate position, a 
position at once forming a faithful index to all its most 
characteristic and essential properties. How far some 
