4 INVERTEBRATE ZOOLOGY 



"Exercise 3. Remove a metathoracic leg and draw an outline 

 of it on a scale of 5. Its different segments, beginning 

 with the proximal one, i.e., the one nearest the body, are 

 the following : the coxa, by which the leg articulates with 

 the body ; the trochanter, a very small segment ; the femur 

 or thigh, a long segment ; the tibia or shank, also long ; the 

 tarsus or foot, which is composed of five small segments, 

 the last one of which bears the two claws. Label all of 

 these. 



Exercise 4. Remove a mesothoracic wing, extend it, and draw a 

 picture of it on a scale of 5, indicating its venation. 



Save your specimen in a dish of formalin or alcohol for future 

 use. We shall reserve the detailed study of the mouth-parts 

 until the grasshopper is taken up, when the mouth-parts of the 

 various orders of insects will be studied together. The internal 

 anatomy of all insects is exceedingly similar, and it will not be 

 necessary to study it in more than one animal ; we select the 

 grasshopper as being the one best suited. 



