126 
NEUROPTERA. 
The head is large and very mobile, with immense compound eyes. 
In some cases the facets on the upper surface are larger than on the lower 
and this difference may be an adaptation to both long and short sight. 
The active habits of these insects necessitates very perfect sight and 
the compound eyes appear to be very highly developed. The antennae 
are small, with few segments, and are bristle-shaped. The mouthparts 
are of the sharp biting type. The thorax is large and the individual seg¬ 
ments consolidated into a srngle mass. The long wings are attached to 
the sides ; the powerful muscles and well-built thorax give the insect 
very great powers of flight. The legs are placed very far forward on the 
thorax and this is apparently an adaptation to the predaceous habits 
of these insects. They catch their prey on the wing, hawking for fly¬ 
ing insects ; the legs extend forwards below the head in the form of a 
basket; as the dragon-fly rushes through the air and pounces on an insect 
the legs grasp the prey and hold it below the head, the dragon-fly remain¬ 
ing in motion throughout. The captive is then devoured. Dragon-flies 
are found only on the wing or resting on twigs, leaves or grass stalks. 
The peculiar position of the legs facilitates this method of repose but 
does not enable the insect to walk. The abdomen is long and thin 
terminated in claspers or processes. The method of fertilization is some¬ 
what remarkable, the seminal fluid which issues from the tip of the ab¬ 
domen being transferred to a pouch on the second abdominal segment, 
which is provided with coupling organs; the male then grasps the female 
by the neck and she brings the tip of her abdomen to this pouch ; in 
some species this process takes place over the water and eggs are laid in 
the intervals of coupling. In others the female descends under water, 
carrying air with her between the wings and body and there deposits her 
eggs; others deposit the eggs while flying over the water, or while 
lying motionless on it with extended wings and a few are known to lay 
them in mud. 
The life history is, so far as known, 
the same throughout the family. Eggs 
are laid in water, a mass of eggs in a 
transparent mucilaginous envelope 
being deposited. The larvae are 
active, with three pairs of legs, short 
Fig, 53 .—Aeschnjd nymph. 
