Respiration by tracheæ, as in insects. The body consists of a head and a
large number of very similar segments, each of which possesses limbs.
One pair of antennæ.
This class is divided into two orders: (1) that of =Centipedes=
(_Chilopoda_), with mouth-parts adapted for seizing prey, and _one_ pair
of legs to each segment; (2) that of =Millipedes= (_Chilognatha_),
adapted for devouring substances resembling humus, also the parts of
plants; and _two_ pairs of legs to each segment. Here belong, above all,
the =Snake Millipedes= (_Julus_) or “False Wireworms” (Fig. 123), of
which several species eat out germinating seeds (peas, beans, mangolds,
and beet), and also attack juicy plant parts (potatoes, turnips,
carrots). Seedlings may be protected by using potatoes to draw away the
millipedes.
[Illustration:
FIG. 123.—Common Snake Millipede (_Julus terrestris_), somewhat
magnified.
]