ARTHROPODS 

 THE GRASSHOPPER 



Melanoplus dOferentialis 



General Appearance. — Observe the shape, color and 

 size. Measure length and greatest width. 



On your drawing tablet make a line of the exact length 

 of the specimen and cross it at the proper place with one as 

 long as the greatest width of the specimen. This diagram 

 represents the longitudinal and lateral axes of the animal. 



Lay the specimen down with the anterior end (head) 

 from you, the posterior end toward you. Note the main 

 differences between the dorsal (upper) side and the ventral 

 (lower) side. On the ventral side note three well-marked 

 divisions of the body, the head, the thorax, and the abdomen. 

 Do you find these three divisions on the dorsal side? Give 

 reason for your opinion. 



What is the nature of the covering? Is it the same all 

 over the body? It is called Chitin. Make a drawing of 

 the animal from the left side showing wings and legs in 

 place (X2). 



The Head. — (i) Turn the animal with head toward 

 you. Note the general appearance from front, sides, and 

 top. Study the face. Near the upper part find the large 

 eyes and the jointed antennae (feelers). Count the seg- 

 ments in the antennae. Is the number the same in both? 

 Why? Is there evidence that one has been broken off? 



20 



