9 o 
THE STUDY OF INSECTS . 
Like the adults, the nymphs are strictly carnivorous. 
They feed on a great variety of insects; and they also 
destroy worms, crustaceans, fish-fry, and tadpoles. 
There are two quite distinct types of insects included 
in this order; these represent two suborders. 
Suborder Anisoptera (An-is-op'te-ra). 
The Dragon-flies . 
The dragon-flies are easily distinguished by the relative 
size of the two pairs of wings, and by the attitude of the 
wings when at rest (Fig. 97). The hind wings are larger 
Fig. 97.—A dragon-fly. 
than the fore wings and are of a somewhat different shape; 
the name Anisoptera, from the Greek anisos , unequal, and 
pteron, wing, refers to this fact. But the most striking 
characteristic is the fact that the wings are extended 
horizontally when at rest. 
Darning-needles, devirs-needles, snake-doctors, spin¬ 
dles, and dragon-flies are some of the names given to these 
insects which dart back and forth over streams and wet 
places, their rapidly moving wings throwing out gleams 
of metallic color as they go. Still more beautiful are they 
when at rest, their wings wide-spread above the abdomen, 
and as rigid and motionless as if made of iridescent glass; 
