DISSECTION OF GRASSHOPPER. 



Are any except the first incomplete ? Lift the parts on 

 the dorsal side of the tip of the abdomen and find the vent. 

 On the dorsal side between the vent and the tenth somite 

 is a broad plate (supra-anal plate), and on either side of 

 this is a small outgrowth from the tenth segment (anal 

 cercus). Are these anal cerci movable ? Could they be 

 regarded as jointed appendages ? To which somite do they 

 belong ? 



In the female study the terminal somites in the same way 

 as in the male. Do you find the same dorsal and ventral 

 halves ? Are any of them hypertrophied ? Do you find 

 vent and anal cerci ? Examine the ovipositor.* Are its 

 parts movable ? See if they are attached to the eighth and 

 ninth segments. 



Draw side and dorsal views of male and female abdo- 

 mens, making each sketch at least five inches long. Insert 

 all features made out, lettering everything. 



In the thorax recognize three segments: prothorax, 

 mesothorax, metathorax, the first overlapping the others 

 something like a cape. How many legs are attached to the 

 prothorax ? Look in the membrane joining the pro- to the 

 mesothorax for a spiracle. Study a prothoracic leg. It is 

 made up of a series of joints. Joining the leg to the body 

 are two short joints (coxa and trochanter), then comes a 

 long femur, next an almost equally long tibia, and lastly, 

 a several-jointed foot or tarsus. Notice how freely the 

 head moves upon the prothorax by means of a flexible 



* As its name implies, the ovipositor is of use in laying the eggs. 

 By means of it the grasshopper bores a hole in the earth, and then the 

 packets of eggs, passing down through the tube formed by the four 

 members of the ovipositor, are deposited in the ground. Other allied 

 species use the ovipositor for placing the eggs in leaf -buds or in the 

 stems of certain plants. 



