72 ANIMAL BIOLOGY 



away and credit given the student on a regular scale. Thus will grading and 

 marks be placed to encourage intelligent study of nature rather than book 

 or laboratory cram. One per cent to be added to the final grade may be cred- 

 ited for every species of pupa, every rare insect (with an observed fact as to its 

 habits) brought in, every bird migration observed, every instance of protective 

 coloration, mimicry (p. 146), outwitting of enemy, instance of injurious insects, 

 and how to combat them, etc. Sharp eyes and clear reasoning will then count 

 as much on school grades as a memory for words or mechanical following of 

 laboratory directions. On scale of 100, class work = 50, examination = 25, 

 field work = 25. 



Collecting Insects. In cities and towns insects, varying with 

 the season, are attracted by electric lights. Beetles and bugs will 

 be found under the lights, moths on posts near the lights, grass- 

 hoppers and crickets and other insects in the grass near by. A 

 lamp placed by a window brings many specimens. In the woods 

 and in rocky places insects are found under logs and stones, and 

 under the bark of dead trees. In open places, prairies, meadows, 

 and old fields with grass and flowers, it will be easy to find grass- 

 hoppers, butterflies, and some beetles. Ponds and streams are 

 usually rich in animal forms, such as bugs and beetles, which swim 

 on or under the surface, and larvae of dragon flies crawling on the 

 bottom. Dragon flies and other insects that lay eggs on the water 

 are found flying in the air above. (In the spring, newly hatched 

 crawfish, tadpoles, and the eggs of frogs and toads should also be 

 collected, if found.) Moths may be caught at night by daubing 

 molasses or sirup made from brown sugar upon the trunks of 

 several trees, and visiting the trees at intervals with a lantern. 



An insect net for catching butterflies and for dredging ponds 

 may be made by bending a stout wire into a circle one foot in 

 diameter, leaving enough straight wire to fasten with staples on an 

 old broomstick. To the frame is fastened a flour sack, or cone 

 made of a piece of mosquito netting. 



Butterflies and moths should be promptly killed, or they will 

 beat their wings to pieces. The quickest method is by dropping 

 several drops of gasoline upon the ventral (under) side of the 

 thorax and abdomen. (Caution : Gasoline should never be used 

 near an open fire, or lamp, as explosions and deaths result from 

 the flame being led through the gasoline-saturated air to the vessel 

 containing it.) 



