74 OUR INSECT FRIENDS AND FOES 



creature comes within the range of the formidable 

 lip. This lip, sometimes called the "mask," is 

 very long, and bears a pair of sharp pincer-like 

 palps ; it is attached to a kind of jointed arm or 

 chin, which is also of considerable length, by a 

 sort of hinge, which permits it to lie close against 

 the under part of the body when not in use. 

 When an unsuspecting victim passes within 

 reach, this formidable and telescopic organ is 

 suddenly thrust out, and its sharp pincer fangs 

 seize the unfortunate insect. 



When about to undergo the final change, the 

 nymph crawls up the stem of a water plant to 

 the surface, and clinging by it legs to the stem 

 of the plant, allows its body to dry in the sun- 

 shine. The first sign of the coming change is 

 the cracking of the skin along the back of the 

 thorax, the slit gradually extending upwards 

 along the neck to the level of the eyes. Gradually 

 the head and the thorax are completely with- 

 drawn, and then the slender legs are disengaged 

 from their sheaths, the insect arching itself back- 

 wards so as to more expeditiously accomplish 

 their withdrawal. Once free from their sheaths, 

 the legs are moved about for a few minutes, as 

 if to test their flexibility, and then the insect 

 rests perfectly motionless for a while, gathering 

 strength for the final effort to free its body, 

 an operation which requires considerable exer- 

 tion. When at last the Dragon-fly has struggled 

 free of its old skin, it has yet to fully develop 

 the full length of its body, and to expand and 

 dry its beautiful wings, before it can take its 

 first flight. So it rests quietly on or beside the 



