POND INSECTS 



75 



mass a number of curious creatures of the appearance shown in 

 figure 47 or figure 48. These are young dragon-flies and can be 

 unmistakablj' known by the peculiar, folded, broad flat under-lip 

 which covers mask -like the whole of the under side of the head, 



(fig. 49). This lower lip can be 

 unfolded and projected some dis- 

 tance in front of the head (fig. 50). 

 Some of these young dragon-flies 

 live on the very bottom of the 

 pond crawling about in the mud 

 and decaying vegetable matter 

 while others cling to the stems of 

 the water plants, some distance 

 above the bottom. The young 

 dragon-flies vary considerably in 

 appearance, but there are two 

 principal groups into which they 



Dragon-fly; short. ^^^ ^^ divided. FirSt, StOUt- 



bodied, usually rather short ones (fig. 47); and second, long slen- 

 der-bodied ones with three usually long, blade-like flaps pro- 

 jecting backward from the posterior tip of the body 

 (fig. 48.). Collect some of both kinds and carry 

 them, in a jar of water, to the school-room. Here 

 they may be kept alive in the still water aquarium, 

 and their feeding habits, and perhaps their trans, 

 formation into adult, winged dragon-flies, observed. 

 Kill one or two of each kind in the cyanide bottle, 

 and examine the bodies. On the back may readily 

 be seen the growing wings. With a pair of forceps 

 or a pin, unfold the hinged lower-lip and note that 

 its broad tip is composed of two jaw-like flaps, each Dra|on-fly; sien 

 fringed on its inner margin with fine teeth. Ex 

 amine the hinge, and note how far this grasping lower-lip is folded. 



Fier. -1'. Yoiu]g 

 thick-bodied kind. 



Fig. -J.^. Youug 

 ragoD-fly; slen- 

 der-bodied kind, 



