INSECTS 



167 



In quiet pools in the brook and in almost any pond 

 may be found water-bugs and water-beetles. Collect 

 various kinds alive and keep in the schoolroom aquarium 

 (p. 332). Running swiftly about on the surface may be 

 seen rather large, blackish, narrow-bodied, long-legged 

 insects known as water-striders or pond-skaters (fig. 123). 

 When at rest they hold 

 the front pair of legs, 

 which are short and stout, 

 projecting forward close 

 to the head, ready to 

 grasp and hold small in- 

 sects, the blood of which 

 they suck by means of 

 a sharp, strong, pierc- 

 ing beak. Their feet 

 make small dents or 

 dimples in the surface 

 film, but do not break- 

 through. Do they ever 

 dive or swim in the 

 water.'' Can they leap.'' Are they winged or wingless.'' 

 The immature water-striders have the body much shorter 

 than that of the adult. To be found also at the surface 

 of the pool are small, oval, flattened, shining black insects 

 that dart swiftly about in curving paths on the water. 

 These are whirligig beetles. Do they run on the water 

 or swim .'' Do they ever dive and swim beneath the sur- 

 face .-' Examine one with a magnifier, and note that it 

 has four compound eyes instead of two, the usual num- 

 ber in insects. Where is the extra pair situated.'' Note 

 the peculiar shape of the legs. What are the legs 

 specially fitted for.' 



Swimming about below the surface may sometimes be 

 found large, shining, black beetles !,fig. 124) from half an 



Fig. 123. — A \\a.ter-strideT, J-yvgroirc-c/ius 

 sp. (From Jenkins and Kellogg.) 



