8 



WHY AND HOW WE STUDY BIOLOGY 



or bobbinet, which should be 18 inches deep and large enough to go 

 over the loop. Such a net can be used for catching flying insects, 

 for dredging or scraping insects out of long grass, and for dipping 



insects or other small 

 animals out of shallow 

 ponds or brooks. 



The cyanide bottle. 

 Cyanide of potassium 

 fumes are best for kill- 

 ing an insect quickly. 

 Since, these fumes are 

 deadly to man as well 

 as other animals, such 

 a bottle must be 

 handled very carefully. 

 To make a cyanide 

 bottle, take a wide- 

 mouthed bottle of 

 about 6 to 8 ounces 

 capacity, and place in 

 it two or three pieces 

 of cyanide of potas- 

 sium the size of a chest- 

 nut. Do not breathe 

 the fumes ! Cover at 

 once with sawdust and 

 pour in liquid plaster 

 of Paris to a depth of 

 about one inch. The plaster will harden quickly. Cork the 

 bottle tightly and keep it closed except when placing insects in- 

 side. Label the bottle like that in the diagram so that you will 

 know it contains a poison. 



Collecting water forms. Some of the members of the party should 

 have quart jars so that living water animals may be captured and 

 brought back alive. Be sure to collect with the fish, frogs, or water in- 

 sects a small amount of some of the green plants growing under water 

 so that you may have living plants to start a balanced aquarium. 



#12 

 "brass 



clo-Ux. 



Read your text and then explain the figure. Can you sug 

 gest any other ways to make an insect net? 



