118 GENERAL BIOLOGY 



the respiratory system, which is made up of a series of 

 branching tubes inside the body for carrying air to the 

 various organs and tissues. There are eight pah's of spiracles 

 in the abdomen, and two in the thorax; determine the 

 exact location of these. 



At the end of the abdomen the somites are considerably 

 modified, to form spines, plates and the like. The hard 

 spines in the female comprise the ovipositor, or egg-laying 

 organ. Determine the number of spines and the relation 

 of these to the somites adjoining. In the male there are 

 smaller spines which function as genital organs during mating. 

 In both males and females the anal opening is dorsal, 

 beneath a chitinous plate, and the reproductive opening 

 is toward the ventral side. 



Make a drawing of the entire animal from the side. 



II. Internal Anatomy. 



Remove the wings and cut along each side of the median 

 dorsal line. Remove the entire dorsal part of the body 

 wall and expose the internal organs. 



1. Respiratory System. Tracheae or air-tubes will be seen 

 as fine white tubes, much branched and extending to all 

 organs and tissues of the body. The tracheae open to the 

 outside through the spiracles. Demonstrate this connection. 



2. Digestive System. Distinguish the following parts: 

 (a) esophagus, leading from the mouth to the crop; (6) 

 crop, a large organ located in the prothorax; (c) gastric 

 caeca, a series of pouches surrounding the posterior end of 

 the crop; how many are there? Do they connect with 

 the cavity of the crop? (d) The stomach is an enlarged 

 part behind the cseca; (e) intestine the posterior portion 



