86 
Dragon-flies and Damsel-flies 
winged imagoes busily going on. The nymphs crawl out of the water, and 
up on stones or projecting sticks, or on bridge-piles or the sides of boats, 
or on the stems of weeds growing by the water’s edge. Here'they cling quietly, 
awaiting the moment when the chi- 
tinous body-wall shall split lengthwise 
along the back of the thorax, and the 
made-over body inside with its damp, 
compressed wings, its delicate trans¬ 
parent skin, and changed mouth-parts 
and legs shall slowly work its way out 
of the old nymphal coat. The nymphs 
of some dragon-flies and damsel-flies 
crawl out among the weeds and grass 
of the shore for some distance before 
choosing a resting-place, and none of 
these will be very readily seen. But careful searching in a place from which 
winged individuals are occasionally arising will- soon reveal the transforming 
in all of its stages (Fig. 116). It takes some time for the emergence of the 
damp, soft imago from the nymphal skin, and some further time for the 
slow expanding and drying of the wings, and the hardening of the body- 
wall so that the muscles can safely pull against it. When all this has come 
about the imago can fly away. But even yet the colors are not fully acquired 
Fig. ii 6.—The issuance of an adult white 
tail, Plathemis trimaculata. (After Need¬ 
ham; natural size.) 
Fig. ii 7.—Adult and last exuvia of the whitetail, Plathemis trimaculata. 
(Natural size.) 
and fixed, and these fresh imagoes have an unmistakably new and shiny 
appearance. They are called teneral specimens. Usually the emergence 
of nymphs from the pond and the subsequent transforming cease by the 
middle of the forenoon, and after that one can And only the frail, drying 
