WHAT AN INSECT IS LIKE: INSIDE 21 



LESSON 2 



Internal Structure 



WORK PROGRAM 



1. Collect minute, transparent nymphs of damselflies* 

 and mayflies from a pond (see p. 182). 



2. Care for this living material indoors until it is needed. 



3. Carefully dissect out the food tube of some large 

 stonefly or grasshopper, and place it in a vial of formalin 

 to be used for demonstration. 



4. Do the same with the ovaries of a large female stone- 

 fly or grasshopper. 



5. Carefully dissect away all of one side of the body 

 of a large stonefly or grasshopper, exposing alimentary 

 canal and brain and ventral nerve ganglia but leaving 

 them all in place so as to show their relations to each other, 

 and put the specimen in a vial of formalin to be used for 

 demonstration. 



6. Assemble materials in the laboratory, including a few 

 permanent slides of cross-section of a stonefly or a damselfly. 



* Small stoneflies are not recommended for this because they are so 

 much harder to keep alive when brought out of the well aerated water of 

 streams into the still water of the laboratory (see page 200). 



