SYSTEM OF INSECTS. 4-17 
lion and motion, in their ovipositor, and in the other 
details of their structure a . 
I have on a former occasion pointed out many of the 
analogies which take place between insects and other 
parts of the animal kingdom, and even between insects 
and the mineral and vegetable kingdoms 5 : I shall now 
resume the subject more at large, but without recurring 
to those last mentioned. In considering the analogies 
which connect insects with other animals, or which they 
exhibit with respect to each other, we may have recourse 
to two methods. We may either consider them as placed 
somewhere between the two extremes of a convolving 
series, from which station we may trace these analogies 
upwards and dowiiwards towards each limit ; or we may 
conceive them and other animals in this respect arranged 
in a number of series that are parallel to each other, in 
which the opposite points are analogous. The first mode 
will perhaps best explain the analogies that exist between 
insects and other animals, and the last those between dif- 
ferent groups of insects themselves. I shall give an ex- 
ample or two of each method, beginning with the first. 
There are two tribes in the animal kingdom that seem 
placed in contrast to each other, both by their habits and 
by their structure. One of these is carnivorous, living 
by rapine and bloodshed, and can seldom be rendered 
subservient to our domestic purposes ; while the other is 
herbivorous or granivorous, is quiet in its habits, and 
easily domesticated. Amongst insects we find the re- 
presentatives of both : those of the first tribe are distin- 
guished by their predaceous habits, by the open attacks, 
or by the. various snares and artifices which they employ 
n Sec above, p, 382—. " b Vol. I. p. 7-. 
VOL. iv. 2 F 
