The abdomen

1. Examine the sting chamber.

2. Cut a window in the side of the abdomen, starting at the rear edge of the tergite of A6.

3. Enlarge the opening towards the posterior end of the abdomen, severing the muscles which hold the isolated parts of the body wall by passing the point of the knife under them.

4. Observe:

   4.1. the spiracle plate of A8, it is found overlying the sting apparatus, and has something of the appearance of a dog's
   head (Plate 5). The spiracle plate is bound to

   4.2. the quadrate plate, near the dog's nose;

   4.3. the proctiger, attached to the sting apparatus and also to

   4.4. the rectum.

5. Remove the contents of the abdomen, lower the walls.

6. Survey the abdominal muscles of the right side (some of them are shown in Fig. 11).