10 DRAGONFLIES OF NORTH AMERICA 
this somewhat disobliging habit there is a most excellent reason. Fleet 
and strong as the dragonfly is, just at the moment of emergence from 
the nymphal skin it is at the mercy of its enemies. Its body, just 
released, has not yet become hardened and toughened. Its wings, 
which have been closely folded in the wing cases of the nymph, are 
tender and easily torn; they are moreover too damp and crumpled 
to sustain the body of the dragonfly in flight. Consequently it is 
well that transformation occurs at that period of the day when there 
is least chance of discovery by enemies. 
For some days before the time of transformation the nymph takes 
no food, but remains quietly clinging to its support, until some 
mysterious impulse causes it to leave the water and crawl up on a 
reed or the strong stem of some other plant. It grasps the reed firmly 
with its sharp tarsal claws; for a fall after the transformation had 
begun might mean death. When it has established itself firmly on the 
reed, it remains for some time motionless; after a time slight move- 
ments of the head and wings are noticed and then a split appears in 
the nymphal skin just behind the head. The back of the emerging 
adult is first drawn through the opening, then the head, the legs and 
wings and lastly the long abdomen. Even when it is thus quite free 
from the old skin the insect is extremely soft and helpless, so it remains 
for a long time clinging to the cast skin, while its wings and body 
become drier and stiffer. After an hour or so the wings are quite dry 
and completely expanded and the dragonfly flies away. 
It is now a full grown insect and has completed the interesting cycle 
of its life, but it still has the pale coloring that characterizes the newly 
emerged insect. Not until somewhat later in adult life does the body 
assume its maturer tints. 
It is now an adult insect and has completed the cycle of its life, but 
it is still teneral, that is, it still has the pale coloring that characterizes 
the newly emerged insect. Not until somewhat later in adult life does 
the body assume its maturer tints, and the chitinous armor harden to 
its full strength. It must fly and forage and feed before its pigmenta- 
tion fully develops. Then if it escapes casualties and enemies and 
lives out the full measure of its days the surface of its armor will grow 
pruinose, developing a whitish bloom: it will become hoary with age. 
