OTHER BEETLES. 79 



biting mouth parts. A number of the common forms 

 should be studied and compared, in order to get a good 

 general idea of the group. A number of species, both 

 large and small, are attracted by a light at night. If a 

 strong light be placed in a window, they may be expected 

 on the screen outside, together with swarms of moths 

 and other insects. Beetles are very commonly found 

 under the bark of logs and stumps and in decaying 

 wood. They may be found along a railroad track, under 

 discarded "cross-ties" or "sleepers." Some gayly colored 

 little beetles are found on flowers; others are common 

 in shallow ponds, where they may easily be taken with 

 a net. These are among the most interesting and attrac- 

 tive of aquarium specimens. "Whirligig beetles" may 

 usually be found on the surface of still water, gyrating in 

 large companies. 



Study a number of the most diverse forms obtainable, 

 following the outline given for the black blister beetle. 

 Then make a comparative study of the structure of all 

 the beetles collected. 



Other common larval forms may be found, as " grubs " 

 and " wire worms " in the soil, and as " borers " in wood. 

 Some larvae may easily be dug with a strong knife from a 

 well-rotted log or stump. 



Pupae will often be found in similar situations. 



Test of Strength. Select one of the stoutest-looking 

 live beetles to be found, and make this simple test of 

 its strength : Mold a saddle of stiff putty that will just 

 fit over its back without interfering with the action of 

 its legs. Hollow this out above, and pour shot into it. 

 Make the load all that the beetle can walk away with. 

 Then, with delicate scales, weigh the load, and also the 

 beetle. If a man weighing one hundred and fifty pounds 

 were as strong in proportion, how much could he carry ? 



