THE DEAGON-FLIES. 



629 



ant of the water, and may be found in most of our streams, usually 

 haunting the muddy banks, and propelling itself along by an appa- 

 ratus as efficacious as it is simple, and exactly analogous to the mode by 

 which the nautilus forces itself through the water. The respiration is 

 carried on by means of the oxygen which is extracted from the water, 

 and the needful supply of liquid is allowed to pass into and out of the 

 body through a large aperture at the end of the tail. 



Such are its means of locomotion ; those of attack are not less re- 

 markable or less efficacious. 



The lower lip, instead of being a simple cover to the mouth, is de- 

 veloped into a strange-jointed organ, which can be shot out to the dis- 

 tance of nearly an inch, or when at rest can be folded flat over the 

 face, much as a carpenter's rule can be shut up so as to fit into his 



The Common Dragon-fly {Libellula depressa). 



pocket, and can be rapidly protruded or withdrawn very much like 

 the instrument called the " lazy tongs." Like that instrument, it is 

 furnished at its extremity with a pair of forceps, and is able to grasp 

 at passing objects with the swiftness and certainty of a serpent's 

 stroke. 



The creature remains for some ten or eleven months in the prelim- 

 inary stages of existence, and when the insect is about to make its final 

 change the undeveloped wings become visible on the back. When its 

 time has come, the pupa leaves the water and crawls up the stem of 

 some aquatic plant until it has reached a suitable elevation ; it clings 

 firmly with its claws, and remains apparently quiet. On approaching 

 it, however, a violent internal agitation is perceptible, and presently 

 the skin of the back splits along the middle, and the Dragon-fly pro- 

 trudes its head and part of the thorax. By degrees it withdraws itself 

 from the empty skin, and sits for a few hours drying itself and shaking 



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