FOURTH WEEK. 



NEEDED. A sauce dish. Some pasteboard cut so as to lay in the 

 bottom of the dish. A sharp-pointed knife or small sharp-pointed scis- 

 sors. A number of grasshoppers. 



FIRST HOUR. With scissors or knife rip the insect open along 

 the side from end to end, then putting a pin through the head and an- 

 other through the harder part of the hind end of the body, stretch the 

 insect out full length on a piece of pasteboard, putting in the pins very 

 obliquely. With other pins spread out the body, exposing all the in- 

 ternal structure, and place the whole under water in the sauce dish. 

 Observe the digestive tract, the air sacs, the sexual organs in the abdo- 

 men, the tracheae in all parts of the body, and, pulling the alimentary 

 tract to one side, notice the heart. Notice further the nervous system 

 along the sternum and the muscles of the thorax. Carefully dissect 

 out the digestive system, noting the pharynx, with the salivary glands, 

 the aesophagus, the crop, with the caeca, the stomach, the ilium, with 

 the Malpighian tubes, the colon, and the rectum, with the rectal glands. 



SECOND HOUR. Dissect out the sexual organs of both sexes, de- 

 scribing their structure. Describe the size and position of the principal 

 air sacs. Dissect out and describe the prominent parts of the nervous 

 system in the body. 



THIRD HOUR. Carefully separate the head from the body, and 

 cut the wall of the head, beginning at the mouth and running back of 

 the eyes, removing the back part. Now pin the head to pasteboard, 

 and, putting it into water, make out carefully the brain, drawing and 

 describing it. 



