39 



The ligament of the viscera \% not attached to the body-wall, but is sup- 

 ported by a large trachea in the third abdominal segment, about which it- 

 forms a collar. This suspensorium has three branches ; one of these ex- 

 tends caudad to the testis or ovary ; one, cephalad, to the heart ; and the 

 third, to the intestine. This last branch receives the tendon of one of the 

 branches of the branched suspensory muscle. 



Make a drawing representing the alimentary canal in the center, a testis or 

 •ovary on each side (these are described in the next section), and the three 

 pairs of suspensoria. While doing this the provisional sketches already 

 made can be utilized, but the observations should be confirmed by a sfudy 

 of the suspensoria of the other side of the specimen. 



Cut the trachea supporting the ligament of the viscera, and slip the liga- 

 ment off from it ; cut the ligament extending to the heart as near to the 

 heart as practicable ; cut the ligament extending to the intestines between 

 the intestine and the tendon of the branched suspensory muscle ; cut the 

 branched suspensory muscle as far cephalad as practicable ; cut off the tip 

 of the testis or ovary, leaving it attached to the ligament ; mount the prepa- 

 ration thus made in glycerine for study with the microscope, carefully spread- 

 ing apart the branches of the ligament and the end of the suspensory muscle 

 with a needle before putting on the cover-glass. Study this preparation 

 with a high power of the microscope and note the difference in structure 

 between the suspensory muscle and the ligament of the viscera. Make a 

 •drawing showing this. 



The suspensory nerves of the alimentary canal extend from the small in- 

 testine to the last abdominal ganglion. They can be best seen in a speci- 

 men opened on the back and will be described later. 



The masticatory organs of the proventriculus. — 



Remove the alimentary canal, and carefully open the proven- 

 triculus by a longitudinal slit. Cover a piece of cork with 

 white paper, spread out the opened proventriculus upon the 

 paper, ental side uppermost, and fasten it in place with rib- 

 bon-pins. Fasten the cork bearing the preparation to the 

 beeswax in a dissecting dish, and cover the preparation 

 with water. Study it with a lens and with a compound 

 microscope, using a low power. Write a description of 

 the masticatory organs, and make a drawing illustrating 

 them. 



