214 NATURAL II 3T0RY. [CH. XII. 



latter has the rudiments of wings packed up in small 

 cases on each side of the insect. 



In this latter state it is supposed that the creature 

 lives at the bottom of the water for a year. It is 

 equally voracious then as in its perfect state. Its 

 body is covered by bits of leaf, wood, and other 

 foreign matters, so as to afford it a complete disguise, 

 while its visage is concealed by a prominent mask, 

 which hides the tremendous apparatus of serrated 

 teeth, and serves as a pincer to hold the prey while 

 it is devoured. 



Its mode of locomotion is equally curious ; for 

 though it can move in any direction, it is not by 

 means of feet or any direct apparatus that it moves, 

 but by a curious mechanism, which has been well 

 illustrated by Reaumur and Cuvier. If one of these 

 nymphs be narrowly observed in water, little pieces 

 of wood and other floating matters will be seen to 

 be drawn towards the posterior extremity of the 

 insect, and then repelled; at the same time that 

 portion of its body will be observed alternately to 

 open and shut. If one of them be placed in water 

 which has been rendered turbid by milk, or coloured 

 with indigo, and then suddenly removed into a more 

 limpid fluid, a jet of the coloured water will be seen 



