% 
4. DEFINITION OF THE TERM JNSECT. 
in another place, has expressly excluded all apods?. 
From other passages in his works, it appears that he re- 
garded the Vermes, &c. either as larvae, or as produced 
spontaneously and not ex ovo?. 
This definition of an insect, though partly founded on 
misconception, as well as his primary division of animals 
in general, is by no means contemptible. If you look at 
a bee or a fly, you will observe at first sight that its body 
is znsected, being divided as it were into three principal 
pieces—head, trunk, and abdomen‘; and if you examine 
it more narrowly, you will find that the two last of these 
parts, especially the abdomen, are further subdivided. 
And this character of insection, or division into segments, 
more or less present in almost every insect‘, is not to be 
found (with the exception of the Crustacea, which Ari- 
* Evromee rorkurodee peev yao est wavte. De Part. Animal. l.iv. c.6. 
> Hist. Animal. 1. iv. c.19. 
* The insection that distinguishes these parts, the abdomen espe- 
cially, is most visible in the majority of the Hymenoptera and Diptera 
orders ; next in some Coleoptera, as the Lamellicorn tribes, &c. and 
the Lepidoptera. Latreille is of opinion, that the two last segments 
of the thorax in some insects are represented by the first of the 
abdomen, and that the upper half segment of this part in Coleoptera 
also rey resents the same. “Latr. De quelques Appendices, &c. An- 
nales Générales des Sciences Physiques. A Bruxelles, vi. livrais. xviii. 
14. In fact, in the Lepidoptera, when the abdomen af separated from 
the trunk, this segment usually remains attached to the latter. In 
the Myriapods, the trunk is to be distinguished from the abdomen 
only by its bearing the three first pair of legs. 
* There is no general rule without exceptions, and no character is 
so universal as to be distinctly exhibited by every member of a class 
or other natural group. Thus, in the majority of the mites (Acarus 
L.) the body is marked by no segments, and the only articulation or 
incision is in the legs, palpi, &c. But as the exception does not make 
void the rule, so neither does the extenuation or absence of some 
primary character at its points of junction with others, in some indi- 
viduals, annihilate the class or group. 
