DRAGONS AND DAMSELS 59 



flies were to thrive and reach maturity, there would 

 be little room on earth for any one else I 



Dragon-fly nymphs taken from the shallow bays 

 of some of our brooks, or from ponds, will thrive in 

 aquaria. Their behavior is diverting, and a study of 

 their anatomy discloses many marvels. Some of them 

 depend on their long, spidery legs to take them 

 about over the floor of the stream. Others are able 

 to expand the posterior end of the alimentary canal 

 so that it fills with water; when occasion demands, 

 they contract the abdomen with force, throwing a jet 

 of water backward and their bodies forward at the 

 same time. They trust to cunning rather than to 

 speed in capturing their prey. Some green ones 

 hang motionless on a water plant, until they seem to 

 passers-by but a part of the landscape. Suddenly 

 they thrust out their sharp claws, and there may 

 be one tadpole less in the water world. A favorite 

 trick of certain others is to cover themselves with 

 bits of rubbish. So completely are they disguised 

 that even the most wary of their neighbors do not 

 detect them. They are thus able to creep stealthily 

 very near to their victims or capture them as they 

 pass. The on-looker whose interest is bound up 

 in the dragon-fly nymphs will find much instruc- 

 tion in the way they catch and handle their cap- 

 tives. A close examination of a specimen will 

 reveal a vicious pair of claws with horny tips. 

 These are at the end of a jointed appendage 

 which serves a double purpose. When folded it 

 is the lower lip, but when extended it becomes 

 a formidable seizing organ. Woe be unto the 



