SYSTEMATIC 
ARRANGEMENT OF INSECTS. 
CLASS VIII. 
INSECTA. 
ARTICULATE animals, with articulate feet. Head distinct, fur- 
nished with two antenne. Heart situated in the back, similar to 
a longitudinal vessel. Organs of respiration tubular, branched, 
distributed throughout the whole body (trachew). Sexes distinct. 
Section I. Apiropoda. 
With numerous feet. With thorax not separate from abdomen. 
OrvER I. Myriapoda. 
Wingless. Jeet numerous (24 or more), disposed according to 
the length of the body, terminated by a single claw. ‘Two clusters 
of simple eyes, in various number; in some no eyes. 
Myriapods. Lace and other modern writers consider this order 
as a class, and wish the name of Insects to be restricted to six~ 
footed articulate animals, of which the body consists of three prin- 
cipal parts: head, thorax, and abdomen. Here there is no separa- 
tion between thorax and abdomen, but the whole body is parted 
into rings. The reason why we have placed these insects at the 
beginning of the class, is to be found in their resemblance to the 
ringed worms, to which they are related, not in their external form 
alone, but also in their internal structure; for even the six-footed 
insects, which undergo complete metamorphosis, often in the larval 
state approximate to the myriapods. We willingly admit, on the 
other hand, that the myriapods accord with certain Crustaceans, and 
even form an unconstrained transition to them. But this natural 
transition is in some degree broken by other insects, which on the 
