THE GRASSHOPPER 3J 



white lines down to the sides of the body and see if you can 

 find where they stop? They may be connected with longi- 

 tudinal lines or with the spiracles. The white lines are 

 tracheae, or air tubes through which the air is conducted 

 to the body. The breathing apparatus, the spiracles, the air 

 tubes, and the air sacs are called the tracheal system. When 

 the animal is living how is the working of this system seen ? 



(3) The large yellowish masses near the posterior end 

 are the egg masses. 



The thin membrane surrounding each mass is the ovary. 

 Carefully pull the white masses aside and try to find the 

 white tube, or oviduct, that leads from them to the ovi- 

 positor. Remove the egg masses with the oviducts from 

 the body. 



Make a drawing of an egg mass and oviduct (X2). 



Remove one of the eggs from the mass, place it on the 

 slide and without cover glass, examine it carefully by means 

 of the low power. 



Do you see a membrane covering the egg? 



Are both ends of the egg alike? 



Make a drawing of the egg. 



(4) The light colored substance between the viscera 

 and the walls of the body is the corpus adiposum. Remove 

 some of it and place it on the slide, cover it with a cover 

 glass and observe with low power objective. You may find 

 colorless blood, tracheal tubes which resemble coils of wire, 

 and muscles. 



Describe in detail each group that you discover. 

 Notice how the tracheal tubes branch until the tubes 

 are very small. 



Make a drawing of the tracheae found. 



